Furthermore, serum TDP-43 levels were significantly lower in the FTD-TDP group (N = 64) compared to the HC group (N = 105) (241.4 pg/mL vs. 361.8 pg/mL, B = 0.268, 95%CI = 0.018–0.517, p = 0.036) after similar adjustments (age and gender), whereas the TDP-43 levels did not significantly differ between the FTD-tau group (N = 27) and the HC group (N = 105) (356.9 pg/mL vs. 361.8 pg/mL, B = − 0.092, 95%CI = − 0.400–0.215, p = 0.554) (Table 1, Fig. 1). Here, MAPT is linked to frontotemporal dementia.