GCM2 and tumor of parathyroid gland: Besides deregulation of the transcription factors TBX1 [6] and GCM2 [5], which are involved in parathyroid embryonic differentiation, and of microRNAs belonging to the early embryonic pluripotent C19MC microRNA cluster [9], parathyroid tumors harbor cells expressing the core stem genes SOX2, POU5F1/OCT4, and NANOG. Recently, SOX2 has been identified as significantly deregulated in parathyroid carcinomas [7].