Pirfenidone treatment results in long-lasting effects and is able to reduce later-stage disease. Mice were transplanted as in Figure 1. Mice were untreated or treated, as indicated, with pirfenidone from days 28 to 56 or days 56 to 84. All mice were evaluated on day 84. (A) Pulmonary function tests on day 84 showed that pirfenidone effects were significant even 4 weeks after treatment cessation. In addition, pirfenidone treatment was effective even when treatment started at late stage (day 56) of the disease. (B) Hydroxyproline assay correlated with pulmonary function test result. (C) Masson’s trichrome staining of lung and liver. (D-E) Quantification of trichrome staining area in the lung and liver. Five to 8 mice were analyzed for each assay. *P ≤ .05, **P < .01, ***P < .001; data are shown as the mean ± SEM.