FGG and Alzheimer disease: A polygenic risk score trained on AD diagnosis has been shown to associate with CSF Aβ levels in the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort.17 Similarly, multiple studies have identified potential blood protein biomarkers of NAB, as reviewed in Voyle et al.18 Of particular interest are replicated markers of NAB including pancreatic polypeptide (PPY) and fibrinogen gamma chain (FGG).16, 18