A form of aggregated tau in neurofibrillary tangles in AD, Paired Helical Filaments (PHF)-tau, is suggested to be polyubiquitinated via not only K48 linkages, but also via non-canonical K6- and K11- linkages (28), whereas soluble tau can be ubiquitinated by K63 (27). The gene discussed is MAPT; the disease is Alzheimer disease.