Explaining directionally biased spread in mouse models of tauopathy is the most natural immediate fit to the current work, as there are many models for which tau pathology has been extensively detailed [11, 13, 36, 37] and the mouse mesoscale connectivity atlas [51] separates efferents from afferents, giving “anterograde” and “retrograde” a precise anatomical meaning. This evidence concerns the gene MAPT and tauopathy.