AQP5 and biliary tract cancer: For example, AQP5 expression is associated with poor prognosis in breast cancer [25–27], hepatocellular carcinoma [28], colorectal carcinoma [29, 30], chronic myelogenous leukemia [31], lung cancer [32, 33], ovarian cancer [34, 35], cervical cancer [36] and oral squamous cell carcinoma [37], but to better outcome in gallbladder [38] and biliary tract cancer [39].