The significance of these phenotypes in the context of cancer immunotherapy remains unresolved, but similar KLRG1+CD127NEG and KLRG1+CD127+ CD8s effector cell populations have been identified in various viral infection models and named short-lived effector cells (SLECs) and double-positive effector cells (DPECs), respectively [24]. This evidence concerns the gene KLRG1 and viral infectious disease.