csf ptau181p concentration data for baseline, year1 and year 2 will bequarantined temporarily due to our discovery that for some individualsamples there appears to be greater analytical variability than shouldbe the case. we are working with the manufacturer of the immunoassayreagents we use for the csf biomarker measurements, innogenetics, andhave worked out a procedural change that eliminates this extraneousnoise. once the retesting analyses are completed the new data will beuploaded with accompanying description.adni biomarker core laboratory at upenn