APOD and Alzheimer disease: Early changes in myelination and oligodendrocytes have been identified with AD,52,53,76-78 including induction of a gene co-expression network within oligodendrocytes in response to early amyloid pathology, with hub genes such as Plp1, Mobp, Apod and Plekhb1,79 thus showing a strong overlap with the ageing-dependent oligodendrocytic networks we identified.