Sporadic nonfamilial parathyroid adenomas, associated with the cyclin D1/PRAD1 oncogene [17], are the classical indication for surgery, while hypercalcemia due to hyperplasia in all parathyroid glands as in the MEN1 syndrome (associated with MEN1 tumor suppressor gene) could be treated with cinacalcet. The gene discussed is CCND1; the disease is multiple endocrine neoplasia type 1.