KLK3 and cancer: Prostate cancer (PCa) is the most frequently diagnosed non-skin tumor and the second leading cause of cancer-related deaths in the male population in most Western countries.[1] With the increasing usage of prostate-specific antigen (PSA) testing, there is an increased tendency to diagnose PCa in developing countries.[1][2] Race, family history and age are the unequivocally accepted risk factors for PCa.