GNAS and tumor of parathyroid gland: McCune–Albright syndrome (somatic activating mutations in GNAS gene) has cafe-au-lait spots, hyper-function of multiple endocrine glands, etc.; autonomous hyper-function most commonly involves the ovary, but also the thyroid (nodular hyperplasia with thyrotoxicosis), adrenal (multiple hyperplastic nodules with Cushing’s syndrome), and pituitary glands (somatotropinomas and prolactinomas), and parathyroid tumors causing HPTH (another type of hereditary HPTH as found in MEN2) [175,176].