FGF2 and neoplasm: CAFs originate mainly from the local resident fibroblasts of the tumor (Arina et al., 2016), which are activated by tumor cell-derived soluble factors such as transforming growth factor beta (TGFβ), platelet-derived growth factor (PDGF), and fibroblast growth factor 2 (FGF2) (Tauriello et al., 2018).