MAPT and Huntington disease: Interestingly, lesions formed by other pathogenic proteins, such as tau and α-synuclein, are also present in HD patient brains (Jellinger, 1998; Charles et al., 2000) and appear in fetal graft tissue (Cisbani et al., 2017; Ornelas et al., 2020), suggesting common pathways driving protein aggregation in these diseases.