GLB1 and Alzheimer disease: In another study, in the brains of patients with AD and AD mouse models, Aβ plaque-associated oligodendrocyte progenitor cells but not astrocytes, microglia, or oligodendrocytes, exhibited a senescence-like phenotype characterized by the upregulation of p21, p16 protein expression, and senescence-associated-beta-galactosidase (SA-β-gal) activity.