CD274 and cancer: A significant number of cases did not show any membranous expression on cancer cells (IRS = 0; PD-1: n = 22, 10.8%, PD-L1: n = 24, 11.7%), and for further statistical analyses we decided to split the study group into cases with no PD-1/PD-L1 expression (IRS = 0) and cases with any expression.