For a mixed population of GZMB+ and GZMK+ CD4+ in melanoma, higher RUNX3 and PRDM1 (BLIMP-1) expression was predominant over low-level TBX21/EOMES expression (Cachot et al., 2021), and the PRDM1 overexpression is supported by similar findings from GZMB+ CD4+ T cells in murine adenoviral infection (Donnarumma et al., 2016). Here, PRDM1 is linked to melanoma.