Transcripts of prostate cancer-associated biomarkers—kallikrein-related peptidase-2 and -3 (KLK2, KLK3), folate hydrolase 1 (FOLH1), and neuropeptide Y (NPY)—were detected in the platelets of cancer patients but not in those of healthy controls. Here, KLK3 is linked to Familial prostate cancer.