TGFB1 and neoplasm: The several key factors contributing to CAF differentiation or activation include transforming growth factor-beta (TGF-β), platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), interleukin-1 (IL)-1β, CXC-chemokine ligand (CXCL)12/stromal cell-derived factor 1, and CC chemokines, which are produced by both tumor and stromal cells [2].