While furin is a convertase activating a range of protein precursors implicated amongst others in BBB disruption (Baumann et al., 2019), alpha-defensins have broad functions including inflammation regulatory effects such as chemotaxis (Fruitwala et al., 2019), and the current HNP1-3 markers have been linked to immunological components of a related illness, Alzheimer's disease (DeMichele-Sweet et al., 2021; Szekeres et al., 2016). This evidence concerns the gene FURIN and early-onset autosomal dominant Alzheimer disease.