WNK2 and male reproductive organ cancer: To delineate the expression and activation of protein kinase pathways in FABP4-induced PrSC activation and PCa cell invasiveness, we investigated the phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways that were reported to be involved in prostate carcinogenesis [37, 38].