CD4 and colorectal neoplasm: Although PD-L1 blockade or CD4+ T cell depletion alone had no impact on tumor vessel perfusion compared with control group, concurrent PD-L1 blockade and CD4+ T cell depletion significantly improved tumor blood vessel perfusion compared with all the other groups in the MCA38 colorectal tumor model (Figures 5(b) and 5(c) and Supplementary Figure S12).