Notably, CD4+ CTLs also expressed multiple kinds of inhibitory receptor (IR) genes, such as PDCD1, CTLA4, LAG3, and HAVCR2, and exhibited co-expression modules analogous to CD4+ regulatory T cells (Tregs), suggesting that they eliminate tumor cells via cytotoxic activity and act as immunosuppressor cells. This evidence concerns the gene CTLA4 and neoplasm.