Thus, PSA levels in male serum above 10 ng/mL are indicative of a serious possibility of prostate cancer, whereas values between 4.0 and 10 ng/mL are not conclusive since they can be due to other pathological situations related to prostate such as prostatitis, benign prostate hyperplasia, etc. [58]. This evidence concerns the gene KLK3 and Familial prostate cancer.