In women with endometrioid adenocarcinomas, PD-L1 expression was significantly associated with FIGO grade in endometrioid adenocarcinoma (p = 0.008); PD-L1 was expressed in six of 52 grade I tumors (11.5%), 15 of 83 grade II tumors (18.1%), and nine of 21 grade III tumors (42.9%). This evidence concerns the gene CD274 and endometrioid adenocarcinoma.