CD274 and endometrial cancer: Multiple clinical trials have proven that the type of POLE hypermutation and MSI are potential beneficiaries of programmed cell death protein (PD-1) and programmed death-ligand 1 (PD-L1) immunotherapies in endometrial cancer (Cancer Genome Atlas Research Network, 2013; Le et al., 2015; Mehnert et al., 2016).