We purified 2N3R and 2N4R recombinant tau substrates and assessed seeding activity in Alzheimer’s Disease (AD) brain samples using either 2N3R only, 2N4R only, or as a 50:50 2N3R and 2N4R molar ratio mixture (Figure 1(a)). The gene discussed is MAPT; the disease is Alzheimer disease.