Although additional functional work is needed to clarify the relationship between sporadic CJD, FKBP5, and the hypothalamic pituitary adrenal (HPA) axis (where FKBP5 plays a major role), it could be that the HPA axis provides a link between the pathology in the brain and the periphery. Here, FKBP5 is linked to sporadic Creutzfeldt-Jakob disease.