Functioning tumors are characterized by hormonal hypersecretion and related signs and symptoms such as acromegaly due to elevated plasma growth hormone (GH) and/or insulin growth factor 1, amenorrhea–galactorrhea or hypogonadism due to hyperprolactinemia, or Cushing's disease due to hypercortisolism. The gene discussed is GH1; the disease is Galactorrhea.