SPP1 and neoplasm: Mast cells are recruited by CCL2, CXCL1, CXCL10, and CXCL8/IL8 and are activated by SCF, VEGF, angiopoietin, PGE2, LTB4, and osteopontin released from the tumor milieu [119], and the activated mast cells produce TGFβ, TNFα, IL1β, and CXCL8 to induce EMT as well as MMP9 to induce degradation of the extracellular matrix for tumor invasion and metastasis [120].