NEFL and Alzheimer disease: Our results add further support to this hypothesis, showing a negative relationship between plasma NfL levels and intracortical myelin content of the right insular cortex, a lightly myelinated cortical region that has shown increased vulnerability in aging (Hu et al., 2014), preclinical (Cantero et al., 2020) and prodromal AD (Cantero et al., 2017).