In cross-sectional adjusted analyses including sex, neopterin and sex × neopterin as independent variables with age, APOE ε4 genotype, Aβ42, p-tau181 and diagnosis as covariates, male sex and high neopterin were significantly associated with increased levels of several kynurenines in the whole cohort, see Table 4; this association was driven by the AD patients, as there were no significant associations with sex or neopterin in the CU group. Here, APOE is linked to Alzheimer disease.