Kodama et al. 2011 showed that deletion of murine-double-minute 2 homolog (MDM2) in mice, a ubiquitin E3 ligase that targets p53 for degradation, resulted in increased hepatocyte apoptosis, elevated synthesis of profibrotic connective tissue growth factor (CTGF), HSC activation, and resultant liver fibrosis. The gene discussed is TP53; the disease is Hepatic fibrosis.