Currently, CSF p-tau181, Aβ42/40, and total tau are used to diagnose AD in clinical practice.1 P-tau217 has recently gained attention due to its high sensitivity and specificity for AD, which are both slightly higher than p-tau181. In plasma, generally speaking, the diagnostic performance of most biomarkers is lower due to difficulties in measuring very low concentrations of abnormal proteins that are present in the blood. The exception is plasma p-tau217, which has excellent diagnostic performance in plasma.2,3 In fact, plasma p-tau217 has statistically non-distinguishable performance from currently used CSF biomarkers. Therefore, plasma p-tau217 will likely have an important role in the future clinical diagnosis of Alzheimer’s disease.2,3