RB1 and neoplasm: Some phase II studies (NCT04592237, NCT03263650) enrolling AVPC used mutations or loss of function events in the tumor suppressors PTEN, RB1, and TP53. Given the key role these genes play in both suppressing lineage plasticity and proliferation (60, 61), enriching clinical trials for patients whose tumors harbor loss of these genes is a pragmatic approach to test treatments predicted to be active in highly proliferative tumors, including NEPC.