Aquaporin-9 (AQP9)

Forms a channel with a broad specificity. Mediates passage of a vast array of non-charged solutes including carbamides, polyols, purines, and pyrimidines in a phloretin- and mercury-sensitive fashion, whereas amino acids, cyclic sugars, Na(+), K(+), Cl(-), and deprotonated monocarboxylates are excluded.

Also permeable to urea and glycerol. .