Furthermore, we have shown that peritoneal macrophages that originate from either aged (26 months) C57BL/6J female mice or Balb/c female mice (18 months) stimulated with tumor-derived factors increased production of TGF-β1 and IL-4, relative to macrophages from young mice [32, 53]. The gene discussed is TGFB1; the disease is neoplasm.