In contrast, mast cells inhibit tumor growth, by releasing IL-1, IL-2, IL-4, IL-6, IL-10 (low expression), monocyte chemotactic protein-3 and -4 (MCP-3 and -4), histamine through H2 receptors, interferon alpha (IFNα), transforming growth factor (TGF)-β, tumor necrosis factor (TNF)-α, and leukotriene B4 (LB4) [15]. The gene discussed is CCL7; the disease is neoplasm.