RB1 and adenocarcinoma: Although clinical data describing the prevalence of protein and genetic perturbations in distinct mCRPC variants is beginning to emerge in the literature, current evidence indicates TP53 mutation and the loss of RB and PTEN are among the most frequently altered molecular aberrations in DNPC, NEPC and adenocarcinoma mCRPC subtypes; TP53 mutation incidence = 57%, 37–67% and 31–40%, respectively, RB1 CNV/mutation/protein loss incidence = 29%, 37–90% and 16%, respectively, and PTEN mutation/CNV/protein loss incidence = 29%, 37–63%, 32%, respectively [4,35,54,55,57].