In these previous studies, pirfenidone treatment was shown to reduce renal fibrosis, as confirmed by ECM-related markers such as collagen, plasminogen activator inhibitor-1 (PAI-1), biglycan, matrix metalloproteinase (MMP)/tissue inhibitor of metalloproteinase (TIMP), and connective tissue growth factor (CTGF). The gene discussed is TIMP1; the disease is renal fibrosis.