CTNNB1 encodes beta-catenin, a central onco-protein regulating the Wingless type (Wnt) pathway, and data suggests that nuclear accumulation of beta-catenin could be an important player in the development of parathyroid adenomas—either through activating mutations or through aberrantly expressed Wnt co-receptors (Fig. 2) [74]. Here, CTNNB1 is linked to parathyroid gland adenoma.