In this line, a retrospective, postmortem study of recipients of cadaver-derived human growth hormone (hGH) found no reported incidence of PD, although the donors of pituitary glands used for hGH preparation probably included people with PD, and pathological α-syn is frequently found in the postmortem pituitary glands of people with PD (Irwin et al., 2013). This evidence concerns the gene GH1 and Parkinson disease.