c-Jun is a critical regulator of liver functions in various contexts: it is required for embryonic liver development (Hilberg et al, 1993), is a limiting factor for hepatocellular carcinoma (HCC) formation induced by chemicals (Eferl et al, 2003), and is necessary for liver regeneration upon partial hepatectomy (Behrens et al, 2002). The gene discussed is JUN; the disease is hepatocellular carcinoma.