PDCD1 and cancer: Accordingly, a combination of high-dose Vit-C (4 g/kg) with anti-CTLA-4 (200 μg) and anti-PD-1 (250 μg) antibodies resulted in significant tumor impairment and remission via the infiltration and activation of anti-cancer adaptive immunity (CD8 T and CD4 T cells), especially CD8 T cells.