Our identification of SEMG2 and TGM2 on LEV/SEV, two protein that are expressed by multiple tissues but overexpressed only in prostate cancer, and nine other prostate specific proteins that are associated with LEV/SEV and also have an altered expression in prostate cancer, is an excellent lead to the identification of prostate cancer-specific EV-associated markers in blood. Here, SEMG2 is linked to Familial prostate cancer.