Furthermore, mast cells modulate the tumour microenvironment by performing a two-pronged role: they perform a pro-neoplastic role by releasing mitogenic and pro-angiogenic factors such as histamine, IL-10, TNF, FGF2, VEGF, IL-18 and MMP20, that promote immune suppression, proliferation and angiogenesis; and they perform an anti-neoplastic role by inhibiting cell growth and motility and promoting antitumour inflammatory reactions and apoptosis21. This evidence concerns the gene MMP20 and neoplasm.