Although only 20% of the included donors met the criteria for mixed MSA + AD pathology (Thal Aβ or Braak NFT stage ≥ 3), a substantial proportion of pure MSA cases exhibited some degree of Aβ or p-tau pathology as reflected by 31% of the total cohort showing Aβ and 91% showing p-tau inclusions in the EntC. This evidence concerns the gene MAPT and multiple system atrophy.