Themean PSA of men under AS and diagnosed (a) with intermediate to high-grade prostatecancer was 5.5 (SD = 4.6); and (b) low-grade prostate cancer was 6.1 (SD = 3.3).Serum PSA was neither a significant predictor of prostate cancer grade in patientssuspected to have prostate cancer (p = 0.75), nor in patients underAS (p = 0.63). Here, KLK3 is linked to Familial prostate cancer.