CD4 and neoplasm: In another series of experiments, we found that treatment with anti-CD25 mAb PC-61, which reduced the absolute number of intratumoral Tregs without concomitant activation of CD4+ Tconv (Figures S9A–S9E), did not have any impact on CD45−CD31high tumor endothelial cells, MECA-79− TA-ECs, and MECA-79+ TA-HECs (Figures S9F–S9H).