In patients suffering a postoperative delirium (POD) following hip fracture surgery or a gastrectomy, two studies (Sunwoo et al., 2013; Yuan et al., 2020) demonstrated that exosome alpha synuclein in blood plasma (Yuan et al., 2020) and alpha-synuclein immunoreactivity in myenteric plexus (Sunwoo et al., 2013) were higher in patients with POD than in those without POD. The gene discussed is SNCA; the disease is delirium.