In the AD brains without LB, we observed a significant (p < 0.0042 considered significant after multiple testing corrections) association between the levels of α-SYN in TBS with Aβ42 in TBSX fractions, α-SYN in TBSX with Tau in TBSX and FA fractions, α-SYN in TBSX with Aβ42 in all three fractions, as well as α-SYN in FA with tau in FA fractions, after adjusting for age at death, sex, CAA score, number of APOE4 alleles, Braak stage, and Thal phase (Table 3). Here, MAPT is linked to Alzheimer disease.