MKI67 and melanoma: While prior studies have shown that the abundance of TILs in the TME is associated with better prognosis and response to ICIs [64–66], we demonstrated that within the pre-treatment melanoma TME, it was the abundance of proliferating antigen-experienced cytotoxic T-cells (CD8 + CD45RO + Ki67+) and their proximity to melanoma cells that best informed on ICI responses in our analyzed cohort [26].