Mast cells can exhibit anti-tumor activity either through: (a) direct tumor cell cytotoxicity and release of tumor necrosis factor or indirectly via mast cell-released heparin actions on fibroblasts, (b) acting as sentinel cells that secrete multiple chemokines that mobilize anti-tumor immune effector cells to tumor sites, (c) modulating immune effector cell responses and differentiation through the release of cytokines or through cell–cell interactions [12,72,74]. This evidence concerns the gene TNF and neoplasm.