MMP9 and neoplasm: Platelets can release granulocyte colony-stimulating factor (G-CSF), macrophage colony-stimulating factor (M-CSF), MMP9, and GM-CSF, increasing the release of bone marrow-derived cells into the circulation, which are recruited to the tumor microenvironment via platelet-derived VEGF, differentiate into mature endothelial cells, and induce the establishment of a tumor vascular network.344 As a result of neovascularization, in the tumor microenvironment, activated platelets secrete a variety of cytokines and growth factors, such as VEGF, CCL5, PDGF, TGF-β, PF4, and HGF.