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HAAO / 3-hydroxyanthranilate 3,4-dioxygenase · IHC design guide
Design Immunohistochemistry for HAAO
HAAO shows strong cytoplasmic staining in liver hepatocytes and kidney proximal tubules (HPA tissue IHC). For paraffin IHC, start antibody A10482 at 2.5 μg/mL (datasheet: A10482) and score staining by cell type (HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
HAAO Immunohistochemistry Experimental Design Guide
Expected localisation, validated protocols, controls and antibodies — the at-a-glance facts below, then the full design guide.
Must know before staining
| Expected localisation | Cytoplasmic in hepatocytes and renal tubules (HPA tissue IHC) | |
| Staining pattern | Strong cytoplasmic hepatocytes and proximal tubules (HPA tissue IHC) | |
| Antigen retrieval | Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen) | |
| Positive control | Kidney+2 more · see all | |
| Negative control | Adipose tissue+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep paraffin-section fixation consistent (standard IHC practice; not target-specific) | |
| Caveat | Signal varies sharply by tissue and cell type (HPA tissue IHC) | |
| Regulation | Liver-enriched expression (HPA tissue IHC) | |
| Isoform / epitope | 2 isoforms; epitope coverage is unspecified (UniProt) |
Section 1
Recommended HAAO IHC & IF Protocols
The catalog antibody’s IHC-P protocol is accompanied by published HAAO IHC conditions for lung, cancer tissue microarrays, and mouse kidney (PMC4448130; PMC9951368; PMC12081153).
| Sample | Tissue sections; selected-image fixative not specified (standard IHC workflow) |
| Fixation | Image fixative and duration unreported (datasheet A10482); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat-induced epitope retrieval in citrate buffer, pH 6.0, 20 min at 95–98 °C (standard rule: cytoplasmic / membrane antigen) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% normal serum of the secondary host, 30 min, room temperature (standard) |
| Primary antibody | Rabbit anti-HAAO, 2.5 μg/mL (datasheet A10482) |
| Primary incubation | Overnight at 4 °C (standard) |
| Detection | HRP-polymer secondary, DAB chromogen 5–10 min (standard) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | HAAO-positive staining in proximal tubules (cell body) of kidney (HPA tissue IHC: High). HPA tissue profile: Selective cytoplasmic expression most abundant in hepatocytes and renal tubules. No signal in the no-primary control. |
💡Decision noteStart with citrate pH 6.0 retrieval at 95–98 °C for 20 min (page antigen-retrieval rule), then compare with the published conditions for your tissue.
Section 2
What Is the Expected HAAO Staining Pattern?
HAAO should show cytoplasmic staining, strongest in hepatocytes and kidney proximal tubule cell bodies, with medium staining in placental decidual cells (HPA tissue IHC: Enhanced; High in hepatocytes and proximal tubules; Medium in decidual cells). This distribution agrees with a cytosolic protein lacking a transmembrane segment (UniProt P46952: cytosol; no transmembrane segment).
| Strong cytoplasmic staining in hepatocytes and proximal tubule cell bodies (HPA tissue IHC: High in both). | This matches the reported selective pattern and expected compartment (HPA tissue IHC: selective cytoplasmic expression; UniProt P46952: cytosol). Compare intensity within the same staining run, because the HPA levels describe observed tissue patterns, not a required numerical threshold (HPA tissue IHC: High). |
| Predominantly nuclear or sharply membrane-localized staining in otherwise positive cells. | Treat this as a localization mismatch and investigate an artefact before calling it HAAO: the reported pattern is cytoplasmic, and HAAO has no annotated transmembrane segment (HPA tissue IHC: selective cytoplasmic expression; UniProt P46952: cytosol, no transmembrane segment). |
| Strong staining in adipocytes, adrenal glandular cells, or respiratory epithelial cells. | These cells are reported as not detected, so strong signal raises concern for cross-reactivity or endogenous detection activity (HPA tissue IHC: Not detected in these cells; general IHC practice). Check the corresponding tissue and detection controls before assigning HAAO positivity (general IHC practice). |
| Diffuse color covers cells and surrounding tissue without a clear cytoplasmic pattern. | This does not support a cell-specific HAAO call (HPA tissue IHC: selective cytoplasmic expression). General IHC causes to assess include excess antibody, incomplete blocking, inadequate washes, and chromogen development; the supplied HAAO sources do not identify a target-specific cause (general IHC practice). |
| No staining in hepatocytes or proximal tubule cell bodies. | An expected positive has failed: both cell types show High staining in the HPA tissue profile (HPA tissue IHC: High in hepatocytes and proximal tubules). Check tissue identity, antibody and detection controls, and the run conditions before interpreting a test specimen as negative (general IHC practice). |
💡Expected HAAO appearanceCall the IHC result consistent with HAAO when strong signal is cytoplasmic in hepatocytes or proximal tubule cell bodies; dominant nuclear, membrane, or unexpected cell staining warrants investigation (HPA tissue IHC: High, selective cytoplasmic expression; UniProt P46952: cytosol; general IHC practice).
| Cellular location and topology (UniProt P46952: cytosol; no transmembrane segment). | Score signal in the cell body cytoplasm rather than using a membrane outline or nuclear deposit as the expected pattern (HPA tissue IHC: selective cytoplasmic expression; UniProt P46952: cytosol). Topology alone does not specify an antigen-retrieval condition (UniProt P46952: topology; general IHC practice). |
| Tissue and cell distribution (HPA tissue IHC: High in hepatocytes and proximal tubules; Medium in decidual cells). | Use liver or kidney as an expected positive reference. Placental decidual cells provide a reported medium-level comparison; adipocytes and several other listed cells are not detected (HPA tissue IHC: cell-level observations). These levels are observations, not universal pass/fail intensity cutoffs (HPA tissue IHC: staining levels). |
| IHC validation (HPA antibodies: HPA036394 and HPA042024, both IHC Enhanced). | The HPA tissue profile has Enhanced reliability, described as high consistency between staining and RNA expression (HPA tissue IHC: Enhanced). This supports the reported IHC pattern; it does not establish how a different antibody or detection system will perform (HPA antibodies: validation status; general IHC practice). |
| Isoforms and processing (UniProt P46952: isoforms 1 and 2; chain 1–286; no signal peptide or propeptide). | Two isoforms are annotated, but the supplied record gives no antibody epitope or isoform-specific staining data (UniProt P46952: two isoforms; HPA antibodies: IHC validation only). Do not interpret a regional staining difference as isoform-specific from these sources alone. |
| IF evidence (HPA subcellular: main location unavailable; no ICC-IF images). | The HPA subcellular record provides no image-based ICC-IF localization for HAAO (HPA subcellular: no ICC-IF images). Its Hep-G2 value is an RNA expression measure, not an IF protein pattern (HPA subcellular: 42.5 nTPM); assess IF on its dedicated guide page. |
| Chromogenic detection background (general IHC practice). | Endogenous enzyme activity can produce color independent of primary-antibody binding in enzyme-based IHC (general IHC practice). Interpret unexpected staining against an appropriate no-primary detection control; HPA's HAAO tissue profile does not identify a sample-specific background mechanism (HPA tissue IHC: tissue observations). |
| Situation | Likely cause | Next action |
|---|---|---|
| The liver or kidney reference has no signal (HPA tissue IHC: High in hepatocytes and proximal tubules). | The run may have failed, or the sampled section may lack the expected cells; the source record does not identify a HAAO-specific failure mechanism (general IHC practice; HPA tissue IHC: positive cells). | Confirm tissue and cell identity, then inspect antibody application, retrieval, detection reagents, and the run control before scoring other sections (general IHC practice). Keep retrieval changes empirical because no HAAO-specific setting is supplied (HPA tissue IHC: no retrieval data). |
| Signal is mainly nuclear or outlines membranes (HPA tissue IHC: selective cytoplasmic expression). | The pattern conflicts with reported HAAO localization (UniProt P46952: cytosol, no transmembrane segment). Nonspecific binding or detection artefact is possible, but the image alone cannot distinguish causes (general IHC practice). | Review the cell morphology and no-primary control, then repeat with adjusted blocking or antibody conditions if the controls implicate background (general IHC practice). Require a cytoplasmic pattern in expected positive cells for interpretation (HPA tissue IHC: selective cytoplasmic expression). |
| Strong color appears in reported negative cell types (HPA tissue IHC: Not detected in adipocytes, adrenal glandular cells, and respiratory epithelial cells). | Cross-reactivity or endogenous detection activity may explain staining outside the reported HAAO distribution (general IHC practice; HPA tissue IHC: negative cell types). A single unexpected cell cannot establish which mechanism applies. | Compare a no-primary control and the expected positive tissue in the same run; review blocking, detection, and antibody concentration if unexpected color persists (general IHC practice). Do not reclassify the HPA-negative cells from color alone (HPA tissue IHC: Not detected). |
| Diffuse background obscures hepatocytes or proximal tubules (HPA tissue IHC: expected positive cells). | High background can conceal cell-level cytoplasmic staining (general IHC practice). Excess reagent, insufficient washing, or overdevelopment are possible general IHC causes; none is a documented HAAO-specific effect in the supplied sources (general IHC practice). | Use the run controls to locate the background source, then optimize blocking, washing, antibody concentration, or chromogen development one variable at a time (general IHC practice). Reassess whether signal is cytoplasmic and cell-selective (HPA tissue IHC: selective cytoplasmic expression). |
| The no-primary section develops color (general IHC practice). | Color without primary antibody points to the detection workflow or endogenous activity, rather than proving HAAO binding (general IHC practice). The HPA tissue observations do not establish a HAAO-specific source of this color (HPA tissue IHC: tissue observations). | Review the detection reagents and the block appropriate to the enzyme system, then repeat the control alongside the positive tissue (general IHC practice). Interpret test-section staining only after the control is acceptable (general IHC practice). |
| Can the HPA IHC pattern be used as an IF/ICC result? | The HPA subcellular record has no ICC-IF images or assigned main location (HPA subcellular: no ICC-IF images; main location unavailable). Its tissue IHC pattern establishes an IHC expectation, not an observed IF distribution (HPA tissue IHC: selective cytoplasmic expression). | Use the separate IF/ICC guide for that application. If assessing IF, require application-appropriate controls and evaluate the observed compartment directly; do not infer IF validation or an IF protocol from the IHC antibody status (HPA antibodies: IHC Enhanced, ICC unreported; general IF practice). |
Experiment evidence
IHC & IF images showing HAAO staining
A10482 · IHCImmunohistochemistry of HAAO in human liver tissue with HAAO antibody at 2.5 μg/mL.
A10482 · IHCImmunohistochemistry of HAAO in mouse colon tissue with HAAO antibody at 2 μg/mL.
A10482 · IFImmunofluorescence of HAAO in Human Liver cells with HAAO antibody at 20 μg/mL.
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000162882-HAAO/tissue/cerebral+cortex#imid_18533539
HPA · Small intestineHuman Protein Atlas IHC, Small intestine. Source: https://www.proteinatlas.org/ENSG00000162882-HAAO/tissue/small+intestine#imid_18533440
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000162882-HAAO/tissue/colon#imid_18533457
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000162882-HAAO/tissue/liver#imid_18533474
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for HAAO IHC & IF
🧪Run liver first: hepatocytes should show HAAO staining (HPA: High in hepatocytes; selected A10482 caption: HAAO staining in human liver). Use adipose tissue as the negative, focusing on adipocytes (HPA: Not detected in adipocytes); on the liver slide, cells outside the hepatocyte population that retain counterstain without specific cytoplasmic chromogen are candidate internal negatives, but their HAAO status is not established by the supplied HPA row (HPA: High in hepatocytes; UniProt P46952: cytosol).
Positive control tissue: Kidney (Proximal tubules (cell body), HPA High)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA carries no ICC-IF cell line for HAAO; derive a cell-line control from the positive tissue's cell type (Proximal tubules (cell body)) and confirm it by RNA or western blot first.
Technical controls: Include no-primary (secondary-only) and concentration-matched isotype controls matched to the primary antibody’s host species and clonality, plus HAAO knockout material or a validated peptide block as a biological specificity control (standard IHC practice). Quench endogenous peroxidase and assess liver pigment before interpreting chromogen signal (standard IHC practice).
⚠️Feasibility: A target-specific fixation window or fixation effect is unreported, and the selected A10482 liver caption does not state a fixative (selected A10482 caption: fixative not stated). Retrieval dependence is unreported, so optimize antigen retrieval empirically for paraffin sections; the supplied evidence does not establish whether frozen sections or IF/ICC are easier (selected A10482 caption: tissue IHC; HPA subcellular: no ICC-IF images). Liver pigment and endogenous peroxidase can complicate chromogenic interpretation (standard IHC practice).
HPA tissue IHC evidence for HAAO
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Enhanced — High consistency between antibody staining and RNA expression data.). Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.
Positive expression · recommended positive controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Kidney | Proximal tubules (cell body) | High | Protein (IHC) | HPA → |
| Liver | Hepatocytes | High | Protein (IHC) | HPA → |
| Placenta | Decidual cells | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Adrenal gland | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced HAAO IHC Tips
Use cytoplasmic staining in hepatocytes and renal tubules as the main reference when optimising HAAO staining in paraffin sections (HPA tissue IHC).
How should I retrieve HAAO in paraffin sections when staining is weak?
Start with citrate buffer at pH 6.0 for heat-induced retrieval at 95–98 °C for 20 min (page retrieval setting). Cool sections consistently before blocking, and compare a retrieved section with a matched section processed without retrieval to judge its effect (standard IHC practice). Evaluate cytoplasmic staining in hepatocytes or renal proximal tubules as positive references (HPA tissue IHC; UniProt P46952 localisation). If staining remains weak, vary retrieval time cautiously while keeping buffer and detection conditions fixed, then check for increased background or tissue damage (standard IHC practice). Record the final retrieval conditions alongside the antibody concentration so repeat runs are comparable (standard IHC practice).
Could fixation explain inconsistent HAAO staining between tissue blocks?
HAAO-specific sensitivity to fixation is unknown from the supplied evidence; the selected A10482 liver caption gives an antibody concentration but does not state a fixative (A10482 tissue-IHC caption). Compare blocks with documented fixation and processing histories, using the same retrieval and detection conditions for each comparison (standard IHC practice). Include liver hepatocytes or kidney proximal tubules on each run to distinguish a block-level problem from a run-level problem (HPA tissue IHC; standard IHC practice). If fixation histories differ, test representative sections side by side before attributing intensity differences to HAAO expression (standard IHC practice). Do not infer fixation tolerance from cytosolic localisation or the absence of annotated glycosylation (UniProt P46952 localisation and glycosylation).
Where should convincing HAAO staining appear within positive cells?
Expect predominantly cytoplasmic, cell-body staining because HAAO is annotated in the cytosol, with no transmembrane segment or signal peptide (UniProt P46952 localisation and topology). Hepatocytes and renal proximal tubule cell bodies provide tissue reference patterns with high staining (HPA tissue IHC). Assess the cytoplasm separately from nuclei and luminal surfaces; a predominantly nuclear or sharply membranous pattern warrants review of controls and morphology (UniProt P46952 localisation; standard IHC practice). Check whether staining follows intact cells across the section rather than appearing only at cut edges or damaged areas (standard IHC practice). Report any unexpected compartment as an observed pattern, not as established HAAO localisation (UniProt P46952 localisation).
Can this antibody distinguish HAAO isoforms in tissue sections?
The record lists 2 HAAO isoforms, but no antibody epitope or isoform-specific validation is supplied (UniProt P46952 isoforms; supplied A10482 evidence). Treat chromogenic staining as HAAO-associated signal without assigning it to isoform 1 or 2 (UniProt P46952 isoforms; standard IHC interpretation). If isoform discrimination matters, obtain the antibody immunogen or epitope sequence and compare it with both isoform sequences before choosing a validation strategy (standard antibody-validation practice). Use an appropriate independent assay to support any isoform claim, because staining intensity alone cannot identify which isoform contributes to a cytoplasmic signal (standard IHC interpretation; UniProt P46952 localisation). Document the epitope evidence with the scoring method (standard reporting practice).
How can I assess HAAO by multiplex immunofluorescence?
Treat IF as an exploratory application here because the supplied evidence includes tissue IHC but no ICC/IF image or IF validation for this antibody (A10482 tissue-IHC caption; HPA subcellular record). Pair HAAO with a validated hepatocyte or renal proximal tubule marker, selecting the marker for the tissue under study (HPA tissue IHC; standard multiplex IF practice). Choose spectrally separated fluorophores and consider a red or far-red HAAO channel where tissue autofluorescence interferes with shorter wavelengths (standard IF practice). HAAO is cytosolic and has no transmembrane segment, so assess intracellular antibody access with gentle permeabilisation after fixation (UniProt P46952 localisation and topology; standard IF practice). Include single-stain and no-primary controls to evaluate bleed-through and background (standard IF practice).
How do I separate HAAO signal from chromogenic background?
First compare hepatocytes or renal proximal tubules with nearby structures and with a no-primary control on the same staining run (HPA tissue IHC; standard IHC practice). Block endogenous peroxidase before a peroxidase-based chromogen, and inspect pigment or precipitate that persists without primary antibody (standard chromogenic IHC practice). Titrate the primary antibody and detection exposure together only after confirming retrieval and tissue integrity; the A10482 liver image used 2.5 µg/mL, without establishing an optimum for every specimen (A10482 tissue-IHC caption; standard IHC practice). Reduce nonspecific staining through appropriate protein blocking and washes, then reassess whether signal remains cytoplasmic and cell-associated (standard IHC practice; UniProt P46952 localisation).
What is a defensible way to quantify HAAO across tissue samples? ⚠ ANSWER MARKED FOR VERIFICATION
Define the compartment and cell population before scoring: use cytoplasmic signal in hepatocytes or renal proximal tubules where those cells are present (UniProt P46952 localisation; HPA tissue IHC). For an H-score, record the percentage of cells at each intensity category and apply the same thresholds to every section; alternatively report the percentage of positive target cells (standard IHC scoring practice). For spatial analysis, report positive-cell density per mm² of viable, annotated tissue, with area measured consistently (standard image-analysis practice). Normalise cell-based results to the number of evaluable cells of the relevant type, and keep retrieval, imaging and chromogen development consistent across comparisons (standard IHC practice).
When should I doubt an apparent HAAO-positive result?
A convincing result follows cytoplasmic staining in intact cells, especially hepatocytes or renal proximal tubules, which have high reported tissue staining (UniProt P46952 localisation; HPA tissue IHC). Predominantly nuclear or membranous signal conflicts with the annotated cytosolic localisation and lacks support from the supplied tissue profile (UniProt P46952 localisation; HPA tissue IHC). Review staining confined to section edges, necrotic regions or damaged tissue against an intact area on the same slide (standard IHC interpretation). Check a no-primary control for endogenous enzyme activity or pigment before calling faint chromogen positive (standard chromogenic IHC practice). Corroborate unexpected cell populations with appropriate controls before describing a new expression pattern (standard IHC practice).
Boster reagents
Best HAAO / 3-hydroxyanthranilate 3,4-dioxygenase IHC Antibodies
The IHC-validated antibody has images of human liver and mouse colon tissue; its IF image shows human liver cells (catalog image captions).
Real IHC data
Anti-HAAO Antibody
Cat # A10482
A10482 is the SKU that will render; its IHC images show human liver and mouse colon tissue (catalog image captions). Its IF image shows human liver cells, and its listed reactivity is Human, Mouse and Rat (catalog image caption; catalog reactivity).
Which to pick: Choose A10482 for tissue IHC: its own images show human liver at 2.5 μg/mL and mouse colon at 2 μg/mL (A10482 IHC image captions); the fixative is unreported. For IF, A10482 has a human liver cell image at 20 μg/mL and lists IF as an application; A10482-1 has an ICC image of Caco-2 cells but does not list IF as an application (catalog IF image captions; catalog applications). For cross-species work, A10482 lists Human, Mouse and Rat reactivity, whereas A10482-1 lists Human and Rat; both list a rabbit host, and neither provides a clone designation (catalog reactivity; catalog host and clone fields).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry P46952 (3HAO_HUMAN, 3-hydroxyanthranilate 3,4-dioxygenase).
- Human Protein Atlas. HAAO tissue IHC expression (reliability: Enhanced).
- Human Protein Atlas. HAAO subcellular location (ICC-IF): Highest expression in Hep-G2: 42.5 nTPM.
- Human Protein Atlas. HAAO antibody validation summary (2 antibodies).
- The proteome of Hypobaric Induced Hypoxic Lung: Insights from Temporal Proteomic Profiling for Biomarker Discovery. Scientific reports 2015 — PMC4448130.
- Tryptophan Metabolism Acts as a New Anti-Ferroptotic Pathway to Mediate Tumor Growth. Advanced science (Weinheim, Baden-Wurttemberg, Germany) 2023 — PMC9951368.
- Identification and Validation of Tryptophan Metabolism-Related Genes in Diabetic Kidney Disease and Construction of a Clinical Prediction Model. Journal of diabetes research 2025 — PMC12081153.
- PubMed PMID:7514594 — UniProt-cited evidence.
- PubMed PMID:14702039 — UniProt-cited evidence.
- PubMed PMID:15815621 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for HAAO (3-hydroxyanthranilate 3,4-dioxygenase). Expected localisation Cytoplasmic in hepatocytes and renal tubules (HPA tissue IHC). Antigen retrieval: Citrate pH 6.0 HIER, 95–98 °C, 20 min (rule: cytoplasmic / membrane antigen). Validated IHC antibody: A10482 at 2.5 μg/mL (the product's own IHC validation image is shown). Controls (HPA): positive Kidney (Proximal tubules (cell body)); negative Adipose tissue. IHC workflow; specimen preparation unspecified. Protocol steps: 1. Sample: Tissue sections; selected-image fixative not specified (standard IHC workflow); 2. Fixation: Image fixative and duration unreported (datasheet A10482); verify before use.; 3. Sectioning: 4–5 µm sections on charged slides (standard); 4. Deparaffinisation: Xylene, graded ethanol series to water (standard); 5. Antigen retrieval: Heat-induced epitope retrieval in citrate buffer, pH 6.0 , 20 min at 95–98 °C…; 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% normal serum of the secondary host, 30 min , room temperature (standard); 8. Primary antibody: Rabbit anti-HAAO, 2.5 μg/mL (datasheet A10482); 9. Primary incubation: Overnight at 4 °C (standard). Watch for: Fixation: Keep paraffin-section fixation consistent (standard IHC practice; not target-specific); Caveat: Signal varies sharply by tissue and cell type (HPA tissue IHC); Isoform / epitope: 2 isoforms; epitope coverage is unspecified (UniProt); Regulation: Liver-enriched expression (HPA tissue IHC). Evidence: UniProt P46952, HPA tissue IHC · Enhanced, HPA cell-line RNA · Highest expression in Hep-G2: 42.5 nTPM, Datasheet A10482, PMC4448130, PMC9951368. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/HAAO/immunohistochemistry-ihc-guide.