This approach was chosen on the grounds that alterations in 3R:4R isoform ratios are centrally involved in the neurodegenerative process [7, 64, 67], associated with specific MAPT variants [22, 25] as well as classes of sporadic tauopathies [21, 43], and are relevant for postmortem diagnostics of tauopathies [34, 43]. This evidence concerns the gene MAPT and tauopathy.