MAPT and neurodegenerative disease: Alpha-synuclein, for example, contributes to the aggregation of beta-amyloid and tau compounds, tau compounds contribute to the aggregation of alpha-synuclein (Pan et al., 2021), and Lewy bodies have been observed not just in Parkinson’s but in other neurodegenerative disease as well (Bendor et al., 2013; Wong and Krainc, 2017).