MAPT and frontotemporal dementia: In the present study, we characterized tau expression, splicing and phosphorylation in control cortical neurons and neurons derived from FTD patients with the 10 + 16 splice-site mutation in MAPT. The 10 + 16 mutation destabilizes a stem loop structure in intron 10 leading to a 2–6-fold increase of exon 10-containing mRNA in patients (15,16).