Relaxin effectively reduces renal fibrosis, with recent research indicating that relaxin suppresses TGF-β activity in human and rat kidney myofibroblast through its receptor RXFP1, activating a pathway dependent on neuronal NOS-NO-cGMP and extracellular signal-regulated kinase phosphorylation (pERK). The gene discussed is TGFB1; the disease is renal fibrosis.