Whole-brain analyses using VBM have only been used to examine the relationship between NfL—measured in CSF, not plasma—and neuronal change in a neurologic illness (frontotemporal dementia) in one previous study.22 However, the current findings are the first to show significant associations between NfL in plasma across the whole brain in both cross-sectional and longitudinal data. This evidence concerns the gene NEFL and frontotemporal dementia.