TBX1 and tumor of parathyroid gland: Verdelli et al. in an in vitro model of parathyroid adenoma-derived cells showed that lithium-induced activation of WNT/β-catenin signaling led to downregulation of the transcription factor TBX1, which is expressed in adult parathyroid cells and deregulated in parathyroid tumors (Figure 1) (102).