AQP9 and colorectal carcinoma: AQP1, AQP3, AQP5, and AQP9 are associated with colorectal cancers [12]; among them, it has been indicated that AQP5 promotes the proliferation and metastasis of CRC [12–14]; moreover, elevated expression of AQP5 in CRC tissue is associated with a poor prognosis of colorectal cancer [15, 16].