Using the quantifiable measure of hydroxyproline for the total collagen content in whole lung tissues, Src inhibitor significantly decreased total collagen levels in bleomycin-challenged mice when compared to that in vehicle treated mice (Fig. 4C, about a 1.25-fold decrease, p < 0.01), demonstrating the Src inhibitor significantly reduced lung fibrosis. The gene discussed is SRC; the disease is pulmonary fibrosis.