Consistent with the reduction of tumor-infiltrating CD8+ T cells, we found that the number of CD4+ cells in MC38 tumors in Vegfb-cKO or Flt1-cKO mice was decreased, and the ratio of IFN-γ+ Th1 and IL-17A+ Th17 cells as well as foxp3+ Tregs in CD4+ T cells were also reduced (Supplemental Figure 12, L–O). This evidence concerns the gene FLT1 and neoplasm.