CD8A and esophageal squamous cell carcinoma: At the advanced unresectable ESCC stage, Wei et al. [99] conducted a phase Ib clinical trial of first-line treatment with RT combined with the anti-PD-1 antibody camrelizumab in patients with locally advanced ESCC who were CCRT intolerant or refused CCRT, versus ESCC patients with CCRT alone for dynamic changes in peripheral blood CD8 T-cell function and differentiation comparison.