The findings revealed a positive relationship between elevated GGT5 expression and immune checkpoint-related genes in most cancer types, particularly in STAD, excluding thymoma (THYM), PCPG, acute myeloid leukemia (LAML), KICH, and bladder urothelial carcinoma (BLCA) (Fig. 3A). This evidence concerns the gene GGT5 and gastric adenocarcinoma.