FGF2 and neoplasm: M2 polarized tumor associated macrophages can either directly activate angiogenesis by releasing VEGF, bFGF and PlGF or indirectly via the release of matrix-metalloproteinases (MMPs), which in turn remodel the extracellular matrix for an enhanced endothelial migration (Kessenbrock et al., 2010; Olson and Joyce, 2015).