TGFB1 and cancer: Several studies have shown that cancer cells could actually secrete signaling molecules, such as basic fibroblast growth factor (bFGF), transforming growth factor beta (TGF-β), platelet-derived growth factor (PDGF), and interleukin- (IL-) 6 to “educate” resting fibroblasts to become CAFs [12–15], and in turn, CAFs promote tumor growth and sustain the stemness property of CSCs in a paracrine manner.