Proteins encoded by ARHGAP4 can regulate the binding between GTPase and rat sarcoma (RAS) family members, whose negative regulation involves the small G protein of the Rho family and associated with tumorigenesis in various cancers, including head and neck squamous cell carcinoma, glioblastoma, breast, lung, pancreatic, liver, colon, and prostate cancers (33, 34). This evidence concerns the gene RAC2 and prostate carcinoma.