In this study, seladelpar demonstrated a robust reduction in liver fibrosis as evidenced by significant reductions in 1) preexisting total collagen as measured by hydroxyproline content (nearly 50%), 2) new collagen I synthesis rate, 3) expression of genes encoding collagens and basement membrane proteins (Col1a1, Col1a2, Col3a1, and Lamb1), and tissue inhibitor of matrix metalloproteinases (Timp1), 4) area stained with fibrosis markers (PSR, α-SMA, Col1a1, Col IV, laminin, and Galectin-3), and 5) the proportion of mice with higher stages of fibrosis. The gene discussed is COL1A1; the disease is Hepatic fibrosis.