FN1 and neoplasm: The ECM is usually remodeled in tumor tissues and promotes desmoplasia, which is characterized by an increase in total levels of fibrillar collagen, fibronectin, proteoglycans, and tenascin C. These changes have been associated with tumor stiffening, which is a more rigid and resistant state that acquires at least 1.5-fold higher resistance to mechanical stress than the surrounding normal tissue.