VEGFA and neoplasm: Enhanced susceptibility of human umbilical vein endothelial cells (HUVECs) to VV was also observed in vitro after cells' exposure to tumor-conditioned media or vascular endothelial growth factor (VEGF).10, 11, 12 The sensitivity of tumor vasculature to VV was initially linked with the enhanced proliferative and metabolic activity of ECs in newly formed vessels and/or overexpression of EGFR on these cells.