CD274 and esophageal squamous cell carcinoma: Current data indicate that the objective remission rate of immune checkpoint inhibitors used alone in the second-line and subsequent treatment of advanced ESCC remains at only about 20% [3,4], and the reasons for this mainly lie in insufficient infiltrating lymphocytes, PD-L1 expression, T cell depletion, tumor-associated macroplyhages, and MDSCs, among other factors, that lead to immunotherapy tolerance [5].