CD274 and esophageal squamous cell carcinoma: Among all ESCC patients, 38 (24.7%) patients were EGFR (+)/PD-L1 (+), 18 (11.7%) patients were EGFR (+)/PD-L1 (−), 43 (27.9%) patients were EGFR (−)/PD-L1 (+), and 55 (35.7%) patients were EGFR (−)/PD-L1 (−).