TGFB1 and cancer: CAFs not only contribute to the desmoplastic stroma by secreting extracellular matrix proteins, but also modulate cancer progression by influencing the production of cytokines/chemokines, such as transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), and CXC chemokine ligand 12 (CXCL12) [20,21].