CD4 and esophageal squamous cell carcinoma: Validation by immunohistochemistry staining suggested that combination with tumor‐infiltrated CD4+ and CD8+ T lymphocytes would yield higher performance of these predictors in distinguishing cases as high‐ or low‐risk of unfavorable prognosis.32 Finally, Thar Min et al. demonstrated that PD‐L1 expression was upregulated in mesenchymal type tumors of esophageal SCC, thus allowing T cell apoptosis in patients with advanced cancer.33