KDR and neoplasm: Integrins, known as adhesion molecules that modulate cell-cell and cell-matrix interactions, have been identified to be expressed on ECs, lymphatic endothelial cells (LECs) and pericytes [28, 29] and participate in tumor angiogenesis by interacting with both the VEGF-VEGFR [30] and ANG-Tie [31–33] pathways.