KLK3 and prostate cancer: Stoffel et al., evaluated peripheral blood for prostate-specific antigen (PSA) producing cells in patients who underwent radical prostatectomy for prostate cancer, preoperatively, in the recovery room and 6 weeks postoperatively.[19] They used a reverse transcriptase polymerase chain reaction (RT-PCR) for their evaluation and found these cells in 88% of the patients in the immediate postoperative period.