KDR and neoplasm: In 2012, our laboratory identified that CD146 can bind with vascular endothelial growth factor receptor 2 (VEGFR2) as a co-receptor required for the activation by vascular endothelial growth factor-A (VEGF-A).53 Because VEGF-A is a well-known growth factor with strong pro-angiogenesis effects, this finding provided the mechanism underlying the roles of CD146 in tumor angiogenesis, especially in sprouting stage.