Barthélemy NR, Bateman RJ, Hirtz C, et al. - Via utilizing the latest quantitative mass spectrometry approach—which achieves a sensitive detection in cerebrospinal fluid biomarker of two phosphorylated tau isoforms, pT181 and pT217—researchers analyzed a cohort of patients with probable Alzheimer disease (AD), patients with other neurological disorders, including tauopathies, and cognitively normal controls. They then checked the validity of their results on a second cohort involving cognitively normal individuals and patients with mild cognitive impairments and AD stratified in terms of their amyloid status based on PiB-PET imaging methods. They found that increased cerebrospinal fluid pT217 levels, more than those of pT181, are highly specific biomarkers for identifying both the preclinical and advanced forms of AD. They noted that their results may help improve the diagnosis of AD in addition to the  correlations found to exist between pT217 levels and PiB-PET data. Overall, pT217 may be a promising potential target for therapeutic applications, and a link may exist between amyloid and tau pathology.