There are several potential explanations for our null results, some of which may reflect limitations of 1H-MRS studies in general, while some of which may have important implications for the spatial and temporal evolution of AD-related biomarkers across the lifespan in APOE E4 carriers (Harris et al. 2020; Jack et al., 2013; Jagust and Mormino, 2011). Here, APOE is linked to Alzheimer disease.