When the effect of gender was considered, males had a trend for slightly higher levels of serum TDP-43, but the age-adjusted gender differences were non-significant in the total study cohort (N = 359, p = 0.052), in the HC group (N = 105, p = 0.072), and in the FTD group (N = 254, p = 0.285). This evidence concerns the gene TARDBP and frontotemporal dementia.