Altogether, our results suggest that combined GARP:TGF-β1/PD-1 blockade exerts anti-tumor activity in MC38 tumors by increasing the density of intratumoral GARP+ blood vessels covered by PDGFRβ+ pericytes, the expression of E-selectin by BECs, and the extravasation and infiltration of T cells, including activated anti-tumor CD8 T cells. The gene discussed is PDGFRB; the disease is neoplasm.