Outline of experimental design in a therapeutic setting. Osmotic pumps containing 200 μL saline with or without bleomycin (BLM; 100 mg/kg) were implanted subcutaneously according to the manufacturer’s instructions. BLM was infused constantly from day 0 to day 6. Pirfenidone (300 mg/kg/day) was orally administered every 12 h from day 10 to day 20. On day 21 of BLM injection, the mice were killed and their lungs were removed for analysis. Each experiment was performed with at least 6 mice per group.