Choi and colleagues developed a 3D iPSC neuron culture model from familial AD patients (mutant APP and mutant presenilin), which, for the first time, represented a disease model that displayed hallmarks of AD pathology: extracellular deposition of amyloid-β, including amyloid-β plaques, and aggregates of phosphorylated tau, as well as filamentous tau (Choi et al., 2014; Kim et al., 2015). Here, MAPT is linked to Alzheimer disease.