MAPT and frontotemporal dementia: Additionally, we generated similar animals using tau variants, either P301S, which is a mutation associated with frontotemporal dementia (FTD), often used in research (Yoshiyama et al., 2007; Takeuchi et al., 2011), or 3PO, which is a lab construct that was optimized to spontaneously aggregate (Iliev et al., 2006) (Figure 1A).