Two hallmarks of AD pathology are amyloid beta (Aβ): A protein which aggregates into extracellular plaques and is formed from cleavage of the APP, and phosphorylated tau (p-tau): A microtubule-associated protein which becomes hyperphosphorylated and accumulates intracellularly (Duyckaerts et al., 2009; see Figure 1 for protein aggregation of each). The gene discussed is MAPT; the disease is Alzheimer disease.