Of the 5 studies utilizing human brain homogenates for disease modeling in NHPs (Table 7), only the two reports by Darricau et al. removed potentially seed-competent contaminants from their donor sources by performing sarkosyl-insoluble tau extractions from PSP and AD patients, respectively (Darricau et al., 2024; Darricau et al., 2022). This evidence concerns the gene MAPT and Alzheimer disease.