APOE and amyloidosis: We also investigated the neurodegenerative proteins MAPT, Aβ38, Aβ40, Aβ42 and the ratio of Aβ42/40, the latter as it has been associated with amyloid plaque deposition in the brain.77 We did not see any relationship between either MAPT or amyloid-β peptide levels and APOE ɛ4 carrier status.