GZMK and cancer: In regard to TFs in GZMK+ CD4+ T cells, our understanding is incomplete; while one report identified overexpression of both EOMES and RUNX3 in human colorectal cancer, generally, these and other TFs were not detected in other cancer contexts (Oh et al., 2020), and in the human dengue viral context, PRDM1 was more associated with the circulating GZMK+ CD4+ T cell subset (Patil et al., 2018).