This isoform of fibronectin is upregulated during times of tissue rearrangement such as wound healing or in diseased states such as cardiac hypertrophy, diabetic nephropathy, tumors, and in liver and pulmonary fibrosis where its expression is often associated with fibrosis or an epithelial-mesenchymal transition in adults [67–69]. Here, FN1 is linked to pulmonary fibrosis.