SRD5A1 and Familial prostate cancer: SRD5A1 and SRD5A3 were the primary isozymes in the prostate cancer cells, and suppression of SRD5A1 and SRD5A3 protein levels was reported to be a promising alternative therapy to block the AR signaling pathway and inhibit the growth of malignant prostate tumors (Uemura et al., 2008; Godoy et al., 2011).