AR and prostate cancer: The molecular changes involved in prostate cancer have not been broadly explored across the Arab world.127 Prostate cancer is more frequent amongst men of African descent, which is attributed to ethnic-specific differences in genotype frequencies for both SRD5A2 and CYP3A4. 137 The CAG repeat length of the androgen receptor also differs according to population and is associated with prostate cancer.138–141 Progress in this area is required in the Arab world.