KLK3 and prostate cancer: Human serum albumin (HSA)is the most abundant protein in plasma.However, the concentration of HSA in the urine of a healthy populationis in the range of 2.2–25 μg/mL, and elevated levelsof HSA indicate kidney malfunction.39 Prostate-specificantigen (PSA) is the most important marker of prostate cancer.40 The concentration threshold, above which thepatient should undergo further testing, is 3 ng/mL.41 Nevertheless, the detection of even lower PSA concentrationsis important when radical prostatectomy is part of prostate cancertreatment.