The characteristic pattern of tau pathology in AD is described by Braak Staging (Braak and Braak, 1991), which begins with the appearance of initial tau lesions in the transentorhinal cortex during stage I. During the subsequent stages of disease progression, the density of tau lesions increases and NFTs spread to the entorhinal cortex in stage II, then to limbic regions of the brain in stage III, before finally reaching the neocortex in stage IV and beyond (Figure 2B). The gene discussed is MAPT; the disease is Alzheimer disease.