GH has been used to treat GH-deficient children for more than 35 years. Human GH originally was obtained from cadaver pituitaries and was available in only limited quantities. In 1985, however, data indicated that pituitary-derived GH was the likely source of contaminated material (prions) responsible for the development of Creutzfeldt-Jakobdisease (CJD) in three young men. CJD is a slowly developing, progressive, and fatal neurologic disorder. Consequently, production and distribution of pituitary GH for therapy were discontinued. CJD has now developed in more than 50 patients who received pituitary-derived GH.