Representative results of aquapore 5 (AQP5) expression by immunostain (A), immunofluorescence (B), and fluorescence in situ hybridization (FISH) (C). (A) Normal tissue negative for AQP5 expression, paraneoplastic tissue negative for AQP5 expression, and tumor tissue with intense AQP5 expression. Paraffin sections were immunostained as described in the Methods section. (B) Immunofluorescence of AQP5 in prostate tissue: fluorescent imaging was obtained with a confocal laser scanning microscope. From top to bottom, AQP5 fluorescence signal in the cancer group, the control, and the paraneoplastic group. (C) AQP5 gene amplification status was detected using FISH. AQP5 gene in cancer group is amplified compared to the control and paraneoplastic group. Con: control, P: paraneoplastic, Ca: cancer.