NTF analysis revealed that plasma levels of BDNF were not different among the four groups (Table 1); levels of PGRN were reduced only in FTD samples compared to CTRL samples (Table 1) (p < 0.01; Kruskal–Wallis test with Dunn’s post test, CTRL vs. FTD, p < 0.01). Here, BDNF is linked to frontotemporal dementia.