TNFRSF1A and neoplasm: Despite the fact that VEGF levels are similar in WT and TNFR1 KO mice, we found that expression of VE-cadherin, a typical endothelial cell marker, was considerably lower in tumors developed in TNFR1 KO mice, suggesting that a decrease in microvessel density may account for the reduction in tumor growth observed in those mice.