FGF2 and neoplasm: Cancer cells-derived secretory molecules, such as basic fibroblast growth factor (bFGF), transforming growth factor beta (TGF-β), platelet-derived growth factor (PDGF), and interleukin- (IL-) 6, transform surrounding fibroblast into CAFs [33–36], and in turn, CAFs promote tumour growth as well as sustain the stemness property of CSCs in a paracrine manner.