Other markers have a strong body of scientific data supporting their role in prostate cancer diagnosis, most notably adenomatous polyposis coli (APC), retinoic acid receptor beta (RARB), RAS association domain family protein 1 (RASSF1), CDH1, CDKN2A (p16), and the O(6)-methylguanine-DNA methyltransferase (MGMT) [22, 24]. Here, RARB is linked to Familial prostate cancer.