MAPT and Alzheimer disease: Moreover, due to the study designs, AD biomarkers for tau pathology differed between patients in BioFINDER-2 and BioFINDER-1; however, the CSF assay (Lilly-developed CSF P-tau217) used for tau in BioFINDER-1 has shown a very high agreement with tau-PET status (used in BioFINDER-2) (ref. 34).