AQP1 and neoplasm: Up to now, at least 13 AQPs been discovered and they are widely and diversely distributed and expressed at different organs and tumors in the role of water reabsorption8, brain-fluid homeostasis9, tumor cell migration10 and angiogenesis11, etc. Tomita et al. 12 speculated that AQP1 may regulate the invasiveness of tumor cells by mediating the Wnt/β-catenin signal pathway and Yoshida et al. 13 found that the overexpression of AQP1was an independently poor prognostic factor for stage II and III colon cancer.