Killer-type lectins are also of interest as markers of cytotoxic CD4+ T cells, and in the GZMB+ subset, KLRG1 is consistently associated with these cells in both human cancers (Zhang et al., 2018; Cachot et al., 2021) and human dengue viral infection (Patil et al., 2018), consistent with an effector phenotype. This evidence concerns the gene CD4 and cancer.