RAMP2+ tumor endothelial cells (TECs) and PROX1+ lymphatic endothelial cells (LECs), were reduced in the PD-1+SMI group and highly expressed VEGF-associated receptor gene KDR (VEGFR1) and FLT1 (VEGFR2) compared with other endothelial subclusters (Fig. 7F). Here, FLT1 is linked to neoplasm.