Recent studies indicate that plasma or CSF levels of NF-L and various tau epitopes are elevated in individuals with MCI who progress to dementia,7–10 but this has not been consistently observed in other studies.6,11,12 Cullen et al. successfully used a combination of plasma levels of Aβ42/40, pTau-181 and NF-L along with age, sex and education for an individualized prognosis of MCI patients10 and achieved an AUC of 0.88 in their study. This evidence concerns the gene NEFL and dementia.