Studies have found a significant correlation between the high expression of CTLA-4 and OS in single nucleotide polymorphisms subgroup cancers, including NPC, esophageal cancer, glioblastoma, and hematologic malignancy, in which CTLA-4 is a good prognostic biomarker.818 CTLA-4 overexpressed NSCLC is associated with a reduced death rate. Here, CTLA4 is linked to esophageal cancer.