VEGFA and neoplasm: VEGF also can reduce the ability of immune cells to adhere and pass through the blood vessel, by down-regulating the integrin ligands intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion protein 1 (VCAM-1) of endothelial cells or preventing them from accumulating on endothelial cells, thus prevent immune cells from entering the tumor (14).