CD4 and neoplasm: Flow cytometry analysis of subcutaneous tumours treated with anti-CTLA-4or anti-PD-1 demonstrated that only anti-CTLA-4 treatment effectively depletedFoxp3+ Tregs (Fig. 5C),resulting in an increase in the ratio of CD8+ and CD4+effector T cells to Tregs (Supplementary Fig. 8D), as previously reported (28).