PSMB1 and Alzheimer disease: Proteasome and ubiquitin mediated proteolysis were also significantly enriched pathways in AD versus Old samples (UBB, UBA7, UBE2O, PSMB1, PSMB4, PSMB8, PSMD2, SKP1, VDAC2) (Table 2 and Supplementary Data S1).