No differences in brain YKL-40 levels were observed neither when the main FTLD pathological subtypes were analyzed separately (FTLD-Tau and FTLD-TDP; Fig. 2A–C) or between their sub-classifications (i.e., PSP, CBD, PiD, MAPT, C9orf72, GRN; Supplementary Fig. 7A-B). Here, C9orf72 is linked to supranuclear palsy, progressive, 1.