These data and the strong correlation between tumor expression of the PD-1 ligand, PD-L1, and positive responses to PD-1 blockade in other cancer types have suggested that the poor results testing anti-PD-1 therapy in CRPC may be due to the lack of PD-L1 expression in PCa tumors [7-9]. This evidence concerns the gene CD274 and posterior cortical atrophy.