NEFL and Alzheimer disease: Studies support the combined use of GFAP with other blood-based biomarkers to improve diagnostic accuracy, particularly in cases involving overlapping comorbidities, progressive neurodegeneration and amyloid accumulation.150 Therefore biomarkers like NfL,151 associated with general neuronal damage, and Alzheimer’s disease-specific biomarkers such as the Aβ1–42/40 ratio and pTau-181 have been explored in conjunction with GFAP.152,153 In a cohort with 252 subjects from Amsterdam Dementia Cohort, Verberk et al.154 demonstrated that combining multiple biomarkers enhances diagnostic accuracy.