SMAD4 and cancer: While in pancreatic cancer cells the increase in TGFβ increases Smad4 but decreases the expression of ALDH1A1,73 the expression of TGFβ stimulates the expression of ALDH and the production of ALDH‐positive cancer stem cells.74, 75 Taken together, these reports suggest a link between the TGFβ signalling pathway and the expression of ALDHs, leading to proliferation of fibro‐adipogenic progenitors and fibrosis, at least in the skeletal muscle.