Recently, IQGAP2 has been considered as a tumor suppressor based on the observed reduction in IQGAP2 in hepatocellular carcinoma, prostate cancer, ovarian cancer and GC, which is further supported by the findings that IQGAP2 deficiency contributed to hepatocellular carcinoma tumorigenesis in mice and cell proliferation and invasion in hepatocellular carcinoma, prostate cancer, and ovarian cancer cell models [25,26,27,28,36]. This evidence concerns the gene IQGAP2 and Familial prostate cancer.