Representative PCR analysis to detect the expression of AQP5 and AQP8 in clinical colorectal samples. (A) Adjacent normal colon tissue. (B) Colorectal carcinoma tissue. AQP5 mRNA was not detected in adjacent normal colon tissue but was abundant in colorectal carcinoma tissue. By contrast, AQP8 mRNA was abundant in adjacent normal colon tissue but was not detected in colorectal carcinoma tissue. β-actin served as the internal control.