To elucidate the potential association between programmed death‐ligand 1 (PD‐L1) and castration resistance in prostate cancer, we analyzed the expression levels of PD‐L1 in both primary prostate cancer tissues and castration‐resistant prostate cancer (CRPC) specimens as well as in corresponding cell lines by using western blots and immunohistochemistry. Here, CD274 is linked to Familial prostate cancer.