VEGFA and neoplasm: However, no correlations with MFG-E8 levels were detected, suggesting in part that alternative mechanisms of macrophage differentiation M2 macrophages are also characterized by the secretion of various cytokines, chemokines, and growth factors, such as the VEGF, a well-known pro-angiogenic protein that has a profound impact on neovascularization and tumor progression [2,24].