Within the tumor microenvironment, acquisition of M2 phenotype is promoted in response to IL-10 and IL-4 cytokines, in addition to some growth factors such as vascular endothelial growth factor A (VEGF-A)158,159 and catecholamines (noradrenaline and adrenaline) released by tumor-associated sympathetic fibers and adrenal glands.160 As with other immunosuppressive cell populations, reducing M2 macrophages likely improves patient prognosis, as it has been recently shown in skin cancer patients. The gene discussed is VEGFA; the disease is neoplasm.