KLK3 and metastatic prostate carcinoma: All serum samples were obtained from patients at least 15 months post-CaP diagnosis and median PSA serum amounts were significantly increased in the CaP (1.20 ± 4.60 ng/ml, ± interquartile range, n = 115) patients (Fig. 1B, p < 0.001) suggesting that this group of patients had recurrent or metastatic prostate cancer.