Additionally, participants with aMCI due to AD had significantly lower levels of Aβ1−42 (p < .001) and Aβ1−42/1−40 (p < .001), and higher levels of p-tau 181 (p < .001) and t-tau (p < .001) compared to participants with MCI due to FTLD, and participants with AD dementia had significantly lower levels of Aβ1−42 (p < .001), Aβ1−42/1−40 (p < .001) and NfL (p = .013), and higher levels of p-tau 181 (p = .036) compared to participants with FTLD dementia. This evidence concerns the gene NEFL and dementia.