FGF9 and Familial prostate cancer: In fact, high FGF9 expression is found in various human tumors such as prostate cancer, non small-cell lung cancer, hepatocellular carcinoma and ovarian endometrioid adenocarcinom, and is significantly associated with the progression of these cancer cells (Cui et al., 2019; He et al., 2018; Wang et al., 2019).