Genetically modified mouse models for liver fibrosis [24, 25] have unraveled effector molecules such as TGF-ß (transforming growth factor beta) [26], PDGF-B [27] (platelet derived growth factor b), PDGF-C (platelet derived growth factor c) [28], or TIMP-1 (tissue inhibitor of metalloproteinase 1) [29], but hepatoprotective factors are not well characterized. The gene discussed is TIMP1; the disease is Hepatic fibrosis.