MET and hepatocellular carcinoma: However, since overexpression of β-cateninS45Y or ∆N90-β-catenin alone does not lead to tumor formation [15, 17, 19], we hydrodynamically injected β-cateninS45Y or ∆N90-β-catenin (both with a Myc tag) together with c-Met, a proto-oncogene frequently overexpressed in human HCC, whose single overexpression does not suffice for HCC development in mice [14], in the mouse liver.