The ECM of the colon mucosa of patients with DM presents high levels of fibrillar collagen (types I and III) and fibronectin with an imbalance between the activities of MMPs and TIMPs and deregulation of the transforming growth factor beta 1 (TGF-β1) pathway associated with the appearance of myofibroblasts and the accumulation of ECM. The gene discussed is TGFB1; the disease is diabetes mellitus.