Plasma NfL accounted for 7.3% of the total association between ILF and dementia (p = 0.01; Figure 2), while serum p-Tau181 mediated 4.9% of the association (p = 0.05; figure not shown) after accounting for baseline age, sex, race, BMI, smoking status, education, comorbidity index and APOE e4. This evidence concerns the gene APOE and dementia.