Macrophage-secreted growth factors, including TGF-β, promote tumor proliferation and remodeling of ECM, and secretion of pro-angiogenic factors and chemokines such as vascular endothelial growth factor (VEGF), inducing the recruitment and activation of fibroblasts, pericytes and endothelial cells to drive blood vessel formation within metastatic tumors [155]. This evidence concerns the gene VEGFA and metastatic neoplasm.