PDGFRB and dementia: There was an interaction effect between age and diagnosis on CSF PDGFRβ (b = 5.3, β = 0.6, 95% CI 0.6–10, p = 0.03), but significant associations between age and CSF PDGFRβ survived in the diagnostic subgroups (CU: b = 18.7, β = 0.5, 95% CI 15–22.4, p < 0.001; MCI: b = 22.2, β = 0.4, 95% CI 13.1–31.2, p < 0.001; dementia: b = 26.5, β = 0.3, 95% CI 15.3–37.7, p < 0.001).