GS positive liver tumors in mice were reported to contain activating mutations of CTNNB1 and to exhibit several features of pericentral hepatocytes, while GS negative tumors carry activating mutations of Ha-ras or B-raf, have features similar to periportal hepatocytes, and were reported to be of no relevance with respect to human HCC [59]. The gene discussed is BRAF; the disease is hepatocellular carcinoma.