Previous investigations of the molecular pathogenesis of sporadic parathyroid adenomas identified recurrent, clonally selected driver mutations in the cyclin D1 (CCND1) proto-oncogene and MEN1 tumor suppressor gene, and a combination of rare germline variants and somatic alterations in several cyclin-dependent kinase inhibitor genes [2-6]. This evidence concerns the gene CCND1 and parathyroid gland adenoma.