The remaining functional tumors are somatotroph adenomas [growth hormone (GH) secreting], corticotroph adenomas [adrenocorticotrophic hormone (ACTH) secreting], thyrotroph adenomas [thyroid-stimulating hormone (TSH) secreting], and gonadotroph adenomas [follicle-stimulating hormone (FSH) and luteinizing hormone (LH) secreting]. Here, GH1 is linked to familial isolated pituitary adenoma.