CD8A and neoplasm: Platinum-based chemotherapy modulates the composition and activity of tumor-infiltrating immune cells, which include increased infiltration of CD8+ T cells, maturation of antigen-presenting cells (APC), and downregulation of regulatory T cells (Tregs) and MDSCs at the tumor sites.25, 26, 27 Increased CD8+ T cell infiltration and CD8+ T cell:Treg ratio was also observed in oxaliplatin-mafosfamide-treated mice, which sensitize the tumor to immune checkpoint blockade.28