MAPT and sarcoma: FTLD can be classified postmortem into four major neuropathological subtypes; FTLD-Tau (hyperphosphorylated tau inclusions), FTLD-TDP (transactive response DNA-binding protein-43; TDP-43), FTLD-FET (fused in sarcoma, Ewing’s sarcoma, TATA-binding protein associated factor 15) and FTLD-UPS (ubiquitin and p62) [2–4].