RB1 and Familial prostate cancer: Our findings demonstrated a lower prevalence of TP53, PTEN, and RB1 alterations in M1-HSPC than is seen in metastatic, castration-resistant prostate cancer; a previous report in this cohort showed an alteration frequency of 50% for TP53, 17% for PTEN, and 10% for RB1 [22].