Missense tau mutations can directly cause familial forms of FTD (Hutton et al., 1998; Strang et al., 2019) and the progression of tau pathology is associated with different tau conformations and prion-like strains that can spread between cell types and in various brain regions (Ayers et al., 2018; Chung et al., 2019). The gene discussed is MAPT; the disease is frontotemporal dementia.