Pro-tumorigenic, metabolically active CAFs, peritumoral fibroblasts, reactive stroma fibroblasts, and myofibroblasts are the major source of ECM molecules.CAFs secrete high levels of collagen I, FNs, laminin, and HA, increasing matrix stiffness.Cancer cells and immune cells also contribute to ECM changes. The gene discussed is TBX1; the disease is cancer.