The results showed that NNMT expression was closely related to the abundance of immune cells infiltrating: cancer-associated fibroblasts (CAFs) in 30 types of tumor, endothelial cells in 27 types of tumor, macrophages in 28 types of tumor, CD8+ T cells in 26 types of tumor, neutrophils in 25 types of tumor, CD4+ T cells in 22 types of tumor, natural killer (NK) cells in 20 types of tumor, and B cells in 11 types of tumor (Table S2). The gene discussed is CD8A; the disease is cancer.