GFAP and NfL concentrations were significantly higher in DLB (GFAP: β = 0.165, 95% CI 0.105–0.225, p < 0.001; NfL: β = 0.130, 95% CI 0.070–0.190, p < 0.001) and AD (GFAP: β = 0.168, 95% CI 0.099–0.237, p < 0.001; NfL: β = 0.086, 95% CI 0.016–0.155, p < 0.05) compared with HC. The gene discussed is NEFL; the disease is Alzheimer disease.