CTNNB1 and hepatocellular carcinoma: CAD expression was not significantly associated with glutamine synthetase (GS) overexpression as an immunohistochemical surrogate parameter of WNT activation in, for example, CTNNB1-mutated HCC [29] (Figure 2d) or with CTNNB1 mutations in the TCGA cohort (Figure 2e, left panel), whereas TP53-mutated tumors exhibited significantly increased CAD expression (Figure 2e, right panel).