A recent study suggested no general contribution for AQP9 to carcinogenesis [84], an interpretation that is in agreement with AQP9 being down-regulated in human hepatocellular carcinoma and its over-expression being allegedly involved in the suppression of hepatoma cell invasion, through the inhibition of the epithelial-to-mesenchymal transition [85]. This evidence concerns the gene AQP9 and hepatocellular carcinoma.