MAPT and early-onset autosomal dominant Alzheimer disease: In addition to the characteristic triplet pattern seen in Alzheimer’s disease with 60, 64 and 69 kDa bands containing 3R- and 4R-tau isoforms, the insoluble tau from Huntington’s disease brains consistently displayed a more complex pattern of weaker bands that confirmed the distinct isoform and/or phosphorylation profiles (Fig. 2A).