The interaction of pathological tau aggregates with ubiquitin linkages is evaluated by immunofluorescence analysis of AD TauO-treated primary neurons in Fig. S3, B and C, which showcase the colocalization of anti-TTCM1 antibody, an in-house monoclonal antibody for toxic tau aggregates (Fig. S3, D–G), with K63-linked ubiquitin (arrow heads), but not with K48-linked ubiquitin, after AD TauO exposure. The gene discussed is MAPT; the disease is Alzheimer disease.