Levels were lowest in individuals with no cognitive impairment [median (interquartile range): neurofilament light chain: 15 (9) pg/mL, phosphorylated tau181: 1.85 (1.00) pg/mL] and highest in those with dementia [neurofilament light chain: 34 (27) pg/mL, phosphorylated tau181: 3.24 (2.81) pg/mL]. This evidence concerns the gene NEFL and dementia.