CD274 and esophageal squamous cell carcinoma: In this study, we extracted IPD from five trials (CheckMate 648 6, ESCORT-first (Luo et al., 2021), JUPITER-06 11, KEYNOTE-590 49, ORIENT-15 29), and found that advanced ESCC patients with low PD-L1 expression can still benefit from anti-PD-1/PD-L1 combinational therapy.