CD8A and melanoma: The effectiveness of immune regulation strategies is closely intertwined with anti-tumor immune responses, involving tumor-related or circulating immune components.23,32,79 Clinical efficacy of anti-PD-1 monoclonal antibody therapy in human melanoma is linked to immune activation in circulating CD8+ T cells that have been depleted.31 This discovery implies that the presence of tumor-specific T cells in the bloodstream may serve as a prognostic indicator for treatment effectiveness.