For the FTD vs. CTRL and FTD vs. AD continuum comparisons we obtained similar results, with an increase of AUC, sensitivity, and specificity but not significantly different from the best performing biomarkers used in isolation (PKM for FTD vs. CTRL, p = 0.59; UCHL1 for FTD vs. AD continuum p = 0.09, DeLong test). Here, UCHL1 is linked to frontotemporal dementia.