For example, in a longitudinal study, a correlation was observed between elevated plasma NFL levels and neuropsychological scores; the baseline plasma NFL level was higher in AD dementia (26.49 ng/ml) than in MCI (17.77 ng/ml) (standardized mean difference = 0.55, 95% CI 0.37–0.73) and normal cognition (15.33 ng/ml)(standardized mean difference = 0.68, 95% CI 0.49–0.88), according to the Clinical Dementia Rating scores (OR = 1.94, 95% CI 1.35–2.79). The gene discussed is NEFL; the disease is dementia.