MAPT and Alzheimer disease: Polygenic risk scores for AD risk did not reliably stratify fast from slow progressors; however, a deeper investigation found that APOE ε4 status predicts amyloid-β and tau positive versus negative patients (odds ratio for an additional APOE ε4 allele = 5.78 [95% confidence interval: 3.76–8.89], P<0.001) when restricting to a subset of patients with available CSF biomarker data.