Once EPCs arrive at the site of damage or near tumor mass, they can take part in neovascularization in three ways: (1) EPCs are directly incorporated in new vessels, (2) EPCs differentiate in mature ECs, and (3) EPCs produce and secrete proangiogenic factor and cytokines with paracrine effects such as VEGF, bFGF, SDF1, PDGF, insulin-like growth factor (IGF1), macrophage inflammatory protein 1a, and monocyte chemotactic protein 1 (MCP1) [68]. The gene discussed is CCL2; the disease is neoplasm.