Researchers have documented cases of Alzheimer's disease that appear to have been transmitted through a medical procedure involving the use of growth hormone extracted from human cadavers. This procedure, which was banned 40 years ago, may have transferred beta-amyloid proteins into the brains of recipients, leading to the development of Alzheimer's. The study suggests that Alzheimer's may be transmissible through certain medical procedures, but emphasizes that it is not contagious in the classical sense. The findings have implications for our understanding of the disease and its potential causes.