To investigate the seeding capacity of these mutant forms of tau, HEK293T FRET reporter cells were transfected with plasmids containing WT SORL1 or SORL1 harboring the G511R or N1358S mutations (Fig. 7A), and then incubated with HMW (highly phosphorylated soluble species that support seeding) or low molecular weight (minimally phosphorylated tau species that do not support tau seeding) (8) SEC fractions from AD patient brain or vehicle control. Here, SORL1 is linked to Alzheimer disease.