Pharmacological delivery of IL-15 significantly reduces TGF-α–induced collagen accumulation and profibrotic cytokines in the lungs of CC10–TGF-α transgenic mice. (A) Light-microscopy photomicrographs of Masson’s trichome–stained lung sections of saline- or IL-15–treated, no-DOX– or DOX-exposed CC10–TGF-α bitransgenic mice are shown. (B–D) Total lung collagen (B) and the profibrotic cytokine TGF-β1 (C), α-SMA (D), and the expression of lung TGF-α (E) in saline- or IL-15–treated, no-DOX– or DOX-exposed TGF-α bitransgenic mice are shown. Data are expressed as mean ± SD, n = 4 mice/group. Scale bars: 100 μm and 20 μm.