(A, B, D) Representative images (20x magnification) from histological sections of murine lung tissue with the following treatments: intratracheal Bleomycin (BLM, left, n=4), Saline (center, n=3), and Bleomycin dual-treated with Imatinib and Lapatinib (BIL, right, n=3; previously shown to be effective in treating BLM-induced fibrosis [23]) were stained with Masson’s Trichrome (A, top) to visualize lung tissue architecture (purple, nuclear; pink, cytoplasmic) and collagen composition (blue, collagen fibers), anti-IGF-1 antibodies (B, middle), anti-phosphorylated-IGF-1R antibodies (D, bottom) co-stained with Hematoxylin, or negative controls (NEG) without primary antibody co-stained with Hematoxylin. Color deconvoluted images (B, D) show the intensity of IGF-1 ligand or phosphorylated-IGF-1R present in BLM mice compared to Saline and BIL per the deconvolution color key and quantified using a pixel count algorithm (C, E). Data are presented as means −/+ Standard Error of the Mean (SEM) for the number of biological replicates indicated (n). Statistical significance was determined after computing single factor ANOVA and/or unpaired two-tailed Student’s t-test (p<0.05 (*), p<0.01 (**), p<0.005 (***), p<0.001 (****). Results demonstrate that IGF-1 ligand and IGF-1R activation are increased in fibrotic murine lung tissue and diminished following anti-fibrotic treatment.