MAPT and Alzheimer disease: As expected, in vitro QC-01–175 and T807 displayed a significantly lower affinity for all recombinant immobilized tau forms than the reported KD of T807 for native, aggregated tau filaments from AD brain sections (KD15 nM) (Chien et al., 2013; Gobbi et al., 2017; Xia et al., 2013).