AQP9 and neoplasm: Therefore, we analyzed the possible pathway with Western blot, the ERK signaling pathway has been considered as a promoter of tumor progression, EMT (Epithelial to Mesenchymal Transition) and invasion [7,20,21,22], AQP9 was shown to promote the activation of ERK1/2 in PC-3 prostate cancer cells, indicating that a possible role for the ERK pathway in AQP9-mediated motility and invasion.