CD274 and glycogen storage disease VI: Therefore, considering that EGFR in EC patients is frequently activated [7, 8, 20, 21] and is positively correlated with PD-L1 expression, our study may provide new insight into the combination of targeting EGFR therapy or chemoradiotherapy with PD-1/PD-L1 targeted immunotherapy, which may expand the population benefiting from immunotherapy and reduce the occurrence of hyper progressive diseases.