To investigate the clinical relevance of SLC22A3 downregulation in prostate cancers, we knocked out SLC22A3 in the prostate cancer C4-2 cell line to assess drug sensitivity to two clinically used anti-prostate cancer drugs, Enzalutamide (AR inhibitor) [31] and JQ1 (BRD4 inhibitor) [32]. This evidence concerns the gene SLC22A3 and Familial prostate cancer.