CD274 and cancer: The expression of PD-L1 has been demonstrated in penile [26,27], vulvar [28,29] and anal [30,31] carcinomas, with different percentages of positive cells, and these previous reports about PD-L1 expression, including TILs presence, in rare cancer tissues had been evaluated using a classic immunohistochemistry (IHC) [26,27,28,29,30,31].