CD274 and cancer: Notably, membranous and/or cytoplasmic PD-L1 expression in lung cancer cells was assessed by immunohistochemistry (IHC) in CheckMate017, CheckMate057 and KEYNOTE010 RCTs [15, 16, 18], but now some studies in various solid cancers have indicated that combined PD-L1 expression on tumor infiltrating lymphocytes and dendritic cells (TILs and TIDCs) in the cancer tumor microenvironment could be important [27–29].