VEGFA and cancer: The tumor microenvironment (TME) is composed of cancer cells, cancer stem cells, endothelial cells, pericytes, cancer-associated fibroblasts, immune and inflammatory cells, as well as extracellular components such as vascular endothelial-derived growth factor (VEGF), ERGF etc., participating in tumor growth, invasion, metastasis, and drug resistance [8, 27].