Outline of experimental design. 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 days 0 to 6. Pirfenidone (300 mg/kg/day) was orally administered every 12 h for 2 wk. On day 14 of BLM injection, the mice were killed and their lungs were removed for analyses. Each experiment was performed with at least 6 mice per group.