Figure 4 shows representative histology images of a patient who died of Alzheimer’s disease with strong Tau expression and pronounced brain atrophy (Panel (a)), as well as a patient who died of COVID-19 with milder expression of Tau and less pronounced brain atrophy, perhaps indicating an early stage of the development of Alzheimer’s disease (Panel (b)). The gene discussed is MAPT; the disease is early-onset autosomal dominant Alzheimer disease.