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ATG9A / Autophagy-related protein 9A · IHC design guide
Design Immunohistochemistry for ATG9A
Plan chromogenic ATG9A IHC in paraffin sections using the cytoplasmic tissue pattern as a reference (HPA tissue IHC). Start the IHC-validated antibody at 2–5 μg/mL and include specificity controls because tissue staining awaits external verification (datasheet A03757-3; HPA tissue IHC).
Evidence assembled Oct 2026 · For research use; verify linked source records and product datasheet before use
ATG9A 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 tissue (HPA tissue IHC); mainly TGN/endosomal at molecular level (UniProt) | |
| Staining pattern | Cytoplasmic staining in several tissues, including glandular cells (HPA tissue IHC) | |
| Antigen retrieval | EDTA pH 8.0 HIER, heat-mediated (datasheet A03757-3) | |
| Positive control | Adrenal gland+4 more · see all | |
| Negative control | Adipose tissue+4 more · see all |
Important caveats
Reasons your staining may differ from the expected pattern.
| Fixation | Keep fixation consistent across sections. (standard IHC practice; not target-specific) | |
| Caveat | Tissue staining awaits external verification (HPA tissue IHC) | |
| Regulation | Starvation redistributes ATG9A to PAS (UniProt) | |
| Isoform / epitope | 3 isoforms; check splice coverage and cytoplasmic versus lumenal epitope (UniProt) |
Section 1
Recommended ATG9A IHC & IF Protocols
The catalog antibody uses EDTA pH 8.0 retrieval (datasheet: A03757-3). These published ATG9A IHC protocols cover mouse central nervous system, mouse tissue, and rat extraction sockets (PMC4076416; PMC9296391; PMC10520003; PMC12314380).
| Sample | Paraffin-embedded human glioma tissue; fixative not specified (datasheet A03757-3) |
| Fixation | Image fixative and duration unreported (datasheet A03757-3); verify before use. |
| Sectioning | 4–5 µm sections on charged slides (standard) |
| Deparaffinisation | Xylene, graded ethanol series to water (standard) |
| Antigen retrieval | Heat retrieval: EDTA pH 8.0 (datasheet A03757-3); 20 min, 95–100 °C (standard) |
| Peroxidase block | 3% H2O2, 10 min, room temperature (standard) |
| Blocking | 10% goat serum (datasheet A03757-3) |
| Primary antibody | Rabbit anti-ATG9A, 2-5μg/ml (datasheet A03757-3) |
| Primary incubation | Overnight at 4 °C (datasheet A03757-3) |
| Detection | Streptavidin-biotin complex (SABC), DAB chromogen (datasheet A03757-3) |
| Counterstain | Hematoxylin, blue, dehydrate and mount (standard) |
| Expected result | ATG9A-positive staining in glandular cells of adrenal gland (HPA tissue IHC: Medium). HPA tissue profile: Cytoplasmic expression in several tissues. No signal in the no-primary control. |
💡Decision noteStart with heat-mediated EDTA pH 8.0 for the catalog antibody (datasheet: A03757-3). Citrate pH 6.0 is a published alternative for rat sections (PMC10520003).
Section 2
What Is the Expected ATG9A Staining Pattern?
ATG9A is a membrane protein that mainly cycles between the trans-Golgi network and endosomal system (UniProt Q7Z3C6 subcellular location; UniProt Q7Z3C6 topology). In paraffin-section IHC, look for cytoplasmic staining in the relevant cells: HPA reports medium staining in bronchial respiratory epithelial cells and several glandular cell populations (HPA tissue IHC). Treat this as a provisional expectation because HPA rates its tissue IHC reliability Uncertain, pending external verification (HPA tissue IHC).
| Cytoplasmic staining in bronchial respiratory epithelial cells or adrenal glandular cells (HPA tissue IHC). | This fits HPA's medium-staining observations for those cell populations (HPA tissue IHC). A granular or perinuclear emphasis is plausible from ATG9A's TGN and endosomal location, but chromogenic IHC alone cannot identify the stained organelle (UniProt Q7Z3C6 subcellular location; general IHC practice). |
| Predominantly nuclear staining, with little cytoplasmic signal. | A nuclear-dominant pattern conflicts with ATG9A's annotated membrane locations and HPA's cytoplasmic tissue profile (UniProt Q7Z3C6 subcellular location; HPA tissue IHC). Review controls and staining conditions before scoring it as ATG9A (general IHC practice). |
| Strong staining in adipocytes or bone-marrow hematopoietic cells. | HPA reports ATG9A as not detected in those specific cell populations (HPA tissue IHC). Unexpected signal warrants checks for antibody cross-reactivity or endogenous chromogenic activity; HPA's Uncertain IHC reliability means the discrepancy alone does not prove either cause (HPA tissue IHC; general IHC practice). |
| Diffuse colour across tissue compartments, including areas outside cells. | Broad background obscures the cell-specific cytoplasmic pattern reported by HPA (HPA tissue IHC). Compare a primary-antibody-omission control, then review blocking, antibody concentration and washing as general IHC checks (general IHC practice). |
| No staining in bronchial respiratory epithelium despite an interpretable section. | HPA reports medium staining in this cell population, so absence merits investigation (HPA tissue IHC). Check section quality, retrieval and detection with appropriate controls before calling the sample negative; the HPA observation remains provisionally reliable (general IHC practice; HPA tissue IHC). |
💡Expected ATG9A appearanceCall a positive result cytoplasmic staining of the relevant bronchial respiratory epithelial or glandular cells, potentially with granular or perinuclear emphasis, near HPA's reported medium level; nuclear-dominant or widespread cell-independent colour is suspect (HPA tissue IHC; UniProt Q7Z3C6 subcellular location; general IHC practice).
| Cell population and tissue selection | HPA reports medium staining in bronchial respiratory epithelial cells, adrenal and several other glandular populations, but no detection in adipocytes or bone-marrow hematopoietic cells (HPA tissue IHC). Choose and score the specified cell population, not the tissue as a whole (general IHC practice). |
| Intracellular distribution | ATG9A mainly cycles between the TGN and endosomal system; starvation or rapamycin can redistribute it toward the phagophore assembly site (UniProt Q7Z3C6 subcellular location). A changed cytoplasmic distribution needs biological context and controls before interpretation (general IHC practice). |
| Topology and antibody epitope | UniProt annotates four transmembrane segments and both cytoplasmic and lumenal regions (UniProt Q7Z3C6 topology). The supplied antibody record gives no epitope position, so it cannot establish which region this IHC assay detects or a target-specific retrieval requirement (HPA antibody record; general IHC practice). |
| Strength of IHC evidence | HPA rates the tissue IHC profile Uncertain, pending external verification, and lists HPA059551 as Uncertain for IHC (HPA tissue IHC; HPA antibody record). Use the reported medium and not-detected examples as provisional comparators, with controls for the actual antibody and run (general IHC practice). |
| IF/ICC: what pattern is expected? | HPA reports vesicles as the supported main ICC-IF location and lists HPA059551 as Supported for ICC (HPA subcellular ICC-IF; HPA antibody record). This supports a vesicular IF interpretation; it does not upgrade that antibody's Uncertain IHC status or supply an IHC tissue result (HPA antibody record; HPA tissue IHC). |
| Situation | Likely cause | Next action |
|---|---|---|
| No signal in an HPA medium-staining cell population. | The run may have inadequate retrieval or detection, or the specimen may differ from HPA's provisional observation (general IHC practice; HPA tissue IHC). | Check section integrity and assay controls, then review retrieval and detection settings; keep the HPA reliability rating in view when interpreting persistent absence (general IHC practice; HPA tissue IHC). |
| Nuclear-dominant signal. | The observed compartment conflicts with the annotated membrane locations and cytoplasmic tissue profile (UniProt Q7Z3C6 subcellular location; HPA tissue IHC). | Compare the primary-antibody-omission control and reassess antibody concentration and detection before assigning ATG9A positivity (general IHC practice). |
| Colour in HPA not-detected cell populations. | Cross-reactivity or endogenous chromogenic activity is possible, although the HPA IHC pattern awaits external verification (general IHC practice; HPA tissue IHC). | Inspect cell identity, compare omission and detection controls, and verify the pattern with an independent antibody if available (general IHC practice). |
| Haze obscures cell borders or cytoplasmic detail. | Nonspecific background can prevent assessment of HPA's reported cytoplasmic expression (general IHC practice; HPA tissue IHC). | Review blocking, primary-antibody concentration and washes; use the omission control to distinguish detection background from primary-antibody-associated staining (general IHC practice). |
| Apparently uniform staining throughout a tissue. | Scoring the whole section can conceal differences between cell populations; HPA assigns staining levels to specified cells (HPA tissue IHC). | Score the named cell types separately, using the counterstain for orientation and including both reported medium and not-detected populations where available (HPA tissue IHC; general IHC practice). |
| Vesicular IF looks convincing, but IHC remains equivocal. | HPA supports the ICC location while rating both its tissue IHC profile and HPA059551 IHC result Uncertain (HPA subcellular ICC-IF; HPA tissue IHC; HPA antibody record). | Interpret each application against its own controls and evidence; do not treat the ICC result as validation of chromogenic IHC staining (general IHC practice; HPA antibody record). |
Experiment evidence
IHC & IF images showing ATG9A staining
A03757-3 · IHCIHC analysis of ATG9A using anti-ATG9A antibody (A03757-3). ATG9A was detected in paraffin-embedded section of human glioma tissue. Heat med
A03757-3 · IHCIHC analysis of ATG9A using anti-ATG9A antibody (A03757-3). ATG9A was detected in paraffin-embedded section of human grastric cancer tissue.
A03757 · IHCImmunohistochemistry of ATG9A in human heart tissue with ATG9A antibody at 5 μg/mL.
A03757 · IFImmunofluorescence of ATG9A in human heart tissue with ATG9A antibody at 20 μg/mL.
M03757 · IHCImmunohistochemical analysis of paraffin-embedded human lung cancer, using ATG9A Antibody.
M03757 · IFImmunofluorescent analysis of Hepg2 cells, using ATG9A Antibody.
A03757-2 · IFIF analysis of ATG9A using anti-ATG9A antibody (A03757-2). ATG9A was detected in immunocytochemical section of A549 cells. Enzyme antigen re
HPA · Cerebral cortexHuman Protein Atlas IHC, Cerebral cortex. Source: https://www.proteinatlas.org/ENSG00000198925-ATG9A/tissue/cerebral+cortex#imid_16372363
HPA · StomachHuman Protein Atlas IHC, Stomach. Source: https://www.proteinatlas.org/ENSG00000198925-ATG9A/tissue/stomach+1#imid_16372255
HPA · ColonHuman Protein Atlas IHC, Colon. Source: https://www.proteinatlas.org/ENSG00000198925-ATG9A/tissue/colon#imid_16372289
HPA · LiverHuman Protein Atlas IHC, Liver. Source: https://www.proteinatlas.org/ENSG00000198925-ATG9A/tissue/liver#imid_16372274
HPA · ICC-IF Hep-G2Human Protein Atlas immunofluorescence, Hep-G2, antibody HPA059551; green = ATG9A, blue = nucleus, red = microtubules.
HPA · ICC-IF Hep-G2Human Protein Atlas immunofluorescence, Hep-G2, antibody HPA059551; green = ATG9A, blue = nucleus, red = microtubules.
← swipe / scroll for more images →
Real IHC / IF data behind the staining-pattern expectations in this section.
Sample controls for ATG9A IHC & IF
🧪Run cerebellum first and score cells in the granular layer, where ATG9A staining is Medium (HPA: cerebellum, cells in granular layer). Use adipose tissue adipocytes as the biological comparison, where staining is Not detected (HPA: adipose tissue, adipocytes); on the cerebellum slide, cells without specific signal should remain at background, but the supplied HPA row does not identify a validated internal negative cell type (HPA: cerebellum, cells in granular layer).
Positive control tissue: Adrenal gland (Glandular cells, HPA Medium)
Negative control tissue: Adipose tissue (HPA Not detected)
ICC-IF cell lines (HPA subcellular resource): HPA ICC-IF images show ATG9A in Hep-G2, MCF-7, U2OS, Sperm, with annotated localisation: Vesicles (supported) (HPA subcellular).
Technical controls: Include a no-primary (secondary-only) control, a concentration-matched rabbit IgG isotype control appropriate to the primary antibody’s clonality, and ATG9A-knockout tissue or cells if available (selected-SKU caption: rabbit primary antibody; standard IHC practice). Quench endogenous peroxidase for DAB detection and assess endogenous biotin when using the caption’s streptavidin–biotin detection system (selected-SKU caption: SABC with DAB; standard IHC practice).
⚠️Feasibility: No target-specific fixation window or fixation effect is reported, and the selected-SKU paraffin-section caption does not state the fixative (selected-SKU caption: fixative not stated). The caption uses heat-mediated retrieval in EDTA at pH 8.0, but does not establish that retrieval is required; no supplied evidence establishes frozen sections or IF as easier than paraffin IHC (selected-SKU caption: EDTA retrieval; HPA: vesicular ICC-IF localization). In cerebellum, check for background from neural-tissue pigment when interpreting chromogenic or fluorescent signal (standard IHC/IF practice).
HPA tissue IHC evidence for ATG9A
Comprehensive Human Protein Atlas IHC scoring per tissue (reliability: Uncertain — Pending external verification.). 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 |
|---|---|---|---|---|
| Adrenal gland | Glandular cells | Medium | Protein (IHC) | HPA → |
| Appendix | Glandular cells | Medium | Protein (IHC) | HPA → |
| Bronchus | Respiratory epithelial cells | Medium | Protein (IHC) | HPA → |
| Cerebellum | Cells in granular layer | Medium | Protein (IHC) | HPA → |
| Cerebral cortex | Neuropil | Medium | Protein (IHC) | HPA → |
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Bone marrow | Hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Breast | Adipocytes | Not detected | Protein (IHC) | HPA → |
| Caudate | Glial cells | Not detected | Protein (IHC) | HPA → |
| Cervix | Glandular cells | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced ATG9A IHC Tips
Use the catalog antibody’s paraffin-section result as a starting point, then judge staining against ATG9A localisation and cell-level controls.
Which retrieval condition should I start with for paraffin sections?
Start with heat-mediated retrieval in EDTA, pH 8.0, for paraffin sections (datasheet A03757-3). The selected tissue image used this condition before incubation with 2 μg/mL primary antibody overnight at 4°C, so keep those variables aligned while assessing retrieval (A03757-3 tissue-IHC caption). Compare retrieved and no-retrieval sections from the same block, judging cellular signal alongside tissue damage and background (standard IHC practice). If staining remains weak, test an alternative retrieval buffer as a fallback on adjacent sections, changing only that variable and retaining the condition that improves interpretable vesicular or cytoplasmic staining (UniProt Q7Z3C6 localisation; standard IHC practice).
How should I troubleshoot weak staining when fixation history is uncertain?
The selected paraffin-section caption does not report its fixative, and no target-specific fixation sensitivity is supplied, so the effect of fixation on this antibody remains unknown (A03757-3 tissue-IHC caption). Record each block’s fixative and fixation history, then compare blocks with similar processing before attributing a signal difference to ATG9A (standard IHC practice). Keep retrieval at EDTA, pH 8.0 and the primary incubation at 2 μg/mL overnight at 4°C during that comparison (A03757-3 tissue-IHC caption). Examine section morphology and staining uniformity, and use an internal cellular reference where available to distinguish a processing problem from a biological difference (standard IHC practice).
What subcellular pattern is plausible in chromogenic ATG9A staining?
Expect predominantly cytoplasmic, often punctate or perinuclear staining: ATG9A mainly cycles between the trans-Golgi network and endosomal system, while HPA reports cytoplasmic tissue expression and supported vesicular localisation (UniProt Q7Z3C6 localisation; HPA tissue IHC; HPA subcellular). Judge the pattern within identifiable cells rather than treating diffuse section-wide DAB as equivalent evidence (standard IHC practice). ATG9A can redistribute toward the phagophore assembly site during amino acid starvation or rapamycin treatment, so document treatment before comparing patterns across specimens (UniProt Q7Z3C6 localisation). A shift in puncta alone does not establish increased autophagic flux; compare matched conditions and use an independent flux readout for that claim (UniProt Q7Z3C6 function; standard IHC interpretation).
How do topology and isoforms affect interpretation of a weak signal?
ATG9A has 3 annotated isoforms and 4 transmembrane segments, with cytoplasmic and lumenal regions that may present differently after processing (UniProt Q7Z3C6 isoforms; UniProt Q7Z3C6 topology). Check the antibody’s stated immunogen or epitope against the isoforms of interest before assuming that a weakly stained section lacks ATG9A (standard IHC practice). The record identifies a glycosylation site at residue 99 and several modified residues, but it supplies no evidence that these modifications alter this antibody’s staining (UniProt Q7Z3C6 glycosylation; UniProt Q7Z3C6 modified residues). Compare adjacent sections under matched retrieval and detection conditions, then use an independent specificity control if epitope recognition remains uncertain (standard IHC practice).
How can IF help assess cell identity and punctate staining?
Use IF as a complementary localisation check for the paraffin-section IHC result, selecting a marker for the cell type being evaluated and assessing whether ATG9A puncta lie within those cells (standard IF practice; UniProt Q7Z3C6 localisation). Choose fluorophores in channels with low tissue autofluorescence and inspect single-channel images before interpreting a merged image (standard IF practice). Match permeabilisation to the antibody epitope: ATG9A contains cytoplasmic and lumenal regions separated by 4 transmembrane segments, while this payload does not identify the catalog antibody’s epitope (UniProt Q7Z3C6 topology; A03757-3 tissue-IHC caption). HPA supports vesicular localisation in ICC/IF, but that observation does not establish IF performance for this catalog antibody (HPA subcellular; A03757-3 tissue-IHC caption).
What should I check when DAB obscures cellular detail?
First inspect a no-primary section for signal from the detection system, and include a peroxidase block before DAB development as a general chromogenic IHC step (standard IHC practice). The selected image used 10% goat-serum blocking, 2 μg/mL primary antibody overnight at 4°C, and biotinylated secondary antibody for 30 minutes at 37°C (A03757-3 tissue-IHC caption). If background persists, assess nonspecific secondary binding, endogenous biotin in a biotin-based workflow, and excess chromogen development on matched control sections (standard IHC practice; A03757-3 tissue-IHC caption). Preserve cellular morphology and a discernible cytoplasmic or vesicular pattern when adjusting detection, since ATG9A is reported in those compartments (HPA tissue IHC; HPA subcellular).
How should I quantify ATG9A staining across paraffin sections? ⚠ ANSWER MARKED FOR VERIFICATION
Define the cell population and region before scoring, then record the percentage of positive cells and staining intensity or calculate an H-score with the same thresholds across slides (standard IHC practice). If puncta are resolvable, report puncta density per mm² of viable tissue or per counted target cell, specifying the denominator and excluding folds, edges, and necrosis (standard IHC practice). Normalize comparisons to the sampled area or target-cell count, and keep retrieval, antibody incubation, chromogen development, imaging, and counterstain consistent (standard IHC practice). Treat HPA’s tissue staining as contextual evidence because its ATG9A tissue-IHC reliability is marked uncertain pending external verification (HPA tissue IHC).
When is ATG9A staining more likely to be genuine?
A plausible positive signal lies in the cytoplasm or vesicle-rich region of identifiable cells, consistent with ATG9A’s trans-Golgi and endosomal cycling and HPA’s supported vesicular localisation (UniProt Q7Z3C6 localisation; HPA subcellular). Compare the stained section with a no-primary control and examine whether signal follows tissue edges, necrotic areas, or endogenous enzyme activity rather than cell boundaries (standard IHC practice). Confirm the scored cell type: HPA reports medium glandular-cell staining in the appendix but no detected staining in liver cholangiocytes, with tissue-IHC reliability marked uncertain (HPA tissue IHC). Neither widespread DAB deposition nor a compartment mismatch should be interpreted as specific ATG9A without independent validation (UniProt Q7Z3C6 localisation; standard IHC practice).
Boster reagents
Best ATG9A / Autophagy-related protein 9A IHC Antibodies
IHC images cover human heart, glioma and lung cancer tissue, and mouse brain; IF images cover human heart tissue and A549 cells (catalog image captions).
Real IHC data
Anti-ATG9A Antibody ®
Cat # A03757-3
Real IHC data
Anti-Autophagy-related protein 9A ATG9A Antibody
Cat # A03757
Real IHC data
Anti-ATG9A Rabbit Monoclonal Antibody
Cat # M03757
Real IF data
Anti-ATG9A Antibody ®
Cat # A03757-2
A03757-3 has IHC images from human glioma and mouse brain, while A03757 has IHC and IF images from human heart tissue (catalog image captions). M03757 has an IHC image from human lung cancer, and A03757-2 has an IF/ICC image from A549 cells (catalog image captions).
Which to pick: For paraffin-section IHC, choose A03757-3: its glioma caption specifies EDTA pH 8 retrieval and 2 μg/mL primary antibody; the fixative is unreported (A03757-3 IHC caption). For IF/ICC, choose A03757-2, which lists both applications and shows staining in A549 cells (A03757-2 applications and IF caption). For work across species, A03757-3 lists human, mouse and rat reactivity and includes a mouse brain IHC image (A03757-3 catalog reactivity and IHC captions).
Each figure is that product's own IHC / IF validation image from its datasheet.
References
- UniProt Consortium. UniProt entry Q7Z3C6 (ATG9A_HUMAN, Autophagy-related protein 9A).
- Human Protein Atlas. ATG9A tissue IHC expression (reliability: Uncertain).
- Human Protein Atlas. ATG9A subcellular location (ICC-IF): Localized to vesicles..
- Human Protein Atlas. ATG9A antibody validation summary (1 antibodies).
- Region-specific changes in the immunoreactivity of Atg9A in the central nervous system of SOD1(G93A) transgenic mice. Anatomy & cell biology 2014 — PMC4076416.
- Activation of the hypoxia response protects mice from amyloid-β accumulation. Cellular and molecular life sciences : CMLS 2022 — PMC9296391.
- Impact of beta-tricalcium phosphate on preventing tooth extraction-triggered bisphosphonate-related osteonecrosis of the jaw in rats. Scientific reports 2023 — PMC10520003.
- Targeting HIF-P4H-2 in APP/PS1 Alzheimer's mouse model improves glucose metabolism, reduces dystrophic neuritis, and maintains exploratory activity. The Journal of biological chemistry 2025 — PMC12314380.
- PubMed PMID:17974005 — UniProt-cited evidence.
- PubMed PMID:15815621 — UniProt-cited evidence.
- PubMed PMID:15489334 — UniProt-cited evidence.
Immunohistochemistry protocol sheet for ATG9A (Autophagy-related protein 9A). Expected localisation Cytoplasmic in tissue (HPA tissue IHC); mainly TGN/endosomal at molecular level (UniProt). Antigen retrieval: EDTA pH 8.0 HIER, heat-mediated (datasheet A03757-3). Validated IHC antibody: A03757-3 at 2-5μg/ml (the product's own IHC validation image is shown). Controls (HPA): positive Adrenal gland (Glandular cells); negative Adipose tissue. IHC-P workflow on paraffin sections; fixative unspecified. Protocol steps: 1. Sample: Paraffin-embedded human glioma tissue; fixative not specified (datasheet A03757-3); 2. Fixation: Image fixative and duration unreported (datasheet A03757-3); 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 retrieval: EDTA pH 8.0 (datasheet A03757-3); 20 min, 95–100 °C (standard); 6. Peroxidase block: 3% H2O2, 10 min , room temperature (standard); 7. Blocking: 10% goat serum (datasheet A03757-3); 8. Primary antibody: Rabbit anti-ATG9A, 2-5μg/ml (datasheet A03757-3); 9. Primary incubation: Overnight at 4 °C (datasheet A03757-3). Watch for: Fixation: Keep fixation consistent across sections. (standard IHC practice; not target-specific); Caveat: Tissue staining awaits external verification (HPA tissue IHC); Isoform / epitope: 3 isoforms; check splice coverage and cytoplasmic versus lumenal epitope (UniProt); Regulation: Starvation redistributes ATG9A to PAS (UniProt). Evidence: UniProt Q7Z3C6, HPA tissue IHC · Uncertain, HPA ICC-IF · vesicles., Datasheet A03757-3, PMC4076416, PMC9296391. QR code links to https://www.bosterbio.com/bosterbio-gene-info-cards/ATG9A/immunohistochemistry-ihc-guide.