Immunotherapy with immune checkpoint inhibitors (ICIs), such as cytotoxic T-lymphocyte-associated protein-4 (CTLA4), programmed death-1 (PD-1), and programmed death-ligand 1 (PD-L1), has improved the clinical outcomes of ESCC patients significantly in recent years [6]. The gene discussed is CTLA4; the disease is esophageal squamous cell carcinoma.