Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes National Hormone and Pituitary Program (NHPP): Information for People Treated with Pituitary Human Growth Hormone (Comprehensive Report) ?
    ### Response:
    We have not found any particular preparation of pituitary hGH that is especially likely to carry CJD. We believe that CJD did not come from a single infected pituitary gland or preparation. Prior to 1977, in an effort to extract as much hormone as possible from the pituitary glands, the glands were often processed repeatedly.
    