MAPT and dementia: In this study, we aimed to: (i) measure CSF levels of PDGFRβ in a cohort comprising subjects with AD and non-AD dementia; (ii) explore the association between PDGFRβ and established biomarkers of amyloid, tau, neuroinflammation, and synaptic impairment to investigate the interplay between neurodegeneration, neuroinflammation, and BBB impairment; and (iii) investigate the relationship between these markers and cognitive status.