MAPT and frontotemporal dementia: We find that both missense and splicing mutations in MAPT alter tau protein localization and phosphorylation within iPSC-derived neurons within 4 months in cell culture, recapitulating a well-described aspect of early FTD pathology in vivo (Götz et al., 1995, Hoover et al., 2010, Kowall and Kosik, 1987), without detectable tau aggregation.