Summary: This study compared the anti-fibrotic efficacy of the newly developed AT2R ligand, β-Pro7 Ang III, which has >20,000-fold selectivity for the AT2R over the AT1R, with the effects of C21 or the FDA-approved medication for treating IPF, pirfenidone, in bleomycin-injured mice with established pulmonary fibrosis. This evidence concerns the gene AGT and pulmonary fibrosis.