CTNNB1 and neoplasm: Expression of the canonical skeletal muscle WNT agonist Wnt5a (WNT5A), canonical WNT receptor Fzd1 (FZD1), and β‐catenin itself (CTNNB1) was all reduced with C‐26 tumor burden, whereas the negative regulator of β‐catenin, GSK3B, was up‐regulated (Fig 8E).