LCN2 and early-onset autosomal dominant Alzheimer disease: LCN2 plays an early role in the pathogenesis of Alzheimer's disease and may serve as an early blood biomarker for Aβ pathology. LCN2 can differentiate VaD from AD with high accuracy, and CSF LCN2 is a promising candidate biomarker for distinguishing VaD from neurodegenerative dementias.