CD8A and melanoma: The CD8+ T cell dependency implies that the transferred NK cells act as an upstream controller for an effective anti-tumor T cell response, which is in line with a previous study showing that early intratumoral accumulation of IFN-γ-producing endogenous NK cells is required for CD8+ T cell-mediated eradication of Cox-deficient melanoma in immunocompetent wild-type mice (Bonavita et al., 2020).