CD274 and esophageal squamous cell carcinoma: A study by Hsieh et al.63advocated that the overexpression of PD‐L1 on cytoplasm is an independent prognostic factor for disease‐free survival in patients who underwent esophagectomy for ESCC and further suggested that patients without overexpression of PD‐L1 and PD‐L2 had a better OS.