Work with TauRD biosensors shows that seed-competent misfolded tau consists of high-molecular-weight phosphorylated oligomers and precedes neurofibrillary tangles in AD patient brain tissues (Holmes et al., 2014; Takeda et al., 2015, 2016; Kaufman et al., 2017; Nobuhara et al., 2017; DeVos et al., 2018; Dujardin et al., 2020). The gene discussed is MAPT; the disease is Alzheimer disease.