GFAP and Alzheimer disease: Already in early stages of AD, a close relationship between GFAP concentration and amyloid burden, as determined by Aβ PET or CSF Aβ42/40 ratio, has been shown in several studies.33,35,39 In DLB, however, inconsistent findings concerning the association of GFAP with Aβ PET have been reported.16,40 As previously suggested, other pathologic processes, such as α-syn deposition causing neuroinflammation,8 could affect astrogliosis,41, -, 44 possibly masking the association of GFAP concentration with amyloid burden in DLB.