A wide range of factors stimulate migration, including VEGF, chemokine ligand 2 (CCL2), chemokine ligand 5 (CCL5), colony-stimulating factor 1 (CSF-1), endothelial monocyte-activating polypeptide II (EMAP-II), endothelin-2, semaphorin 3A (SEMA3A), oncostatin M, and eotaxin, are produced in tumor hypoxic microenvironment leading to massive infiltration and entrapment of macrophages in these oxygen-deficient areas [59, 99]. Here, VEGFA is linked to neoplasm.