KLK3 and Familial prostate cancer: For example, examining PCA3 and PSA expression in peripheral blood, Vaananen et al reported that PCA3 nucleic acid was amplified positively from two out of nine patients with metastasis phenotypes, eight samples were PSA positive, no PCA3 expression in healthy individuals from a cohort of 91 tested prostatic cancer/disorder patients and healthy controls [16].