Gene expression-based survey of more than 600 patient samples revealed three major molecular classes of HCC termed S1, S2 and S3, one of which (subclass S1) is characterized by strong activation of Wnt pathway gene expression signature and the other (subclass S3) by high frequency of activating CTNNB1/ β-catenin mutations [15]. Here, CTNNB1 is linked to hepatocellular carcinoma.