Research into AD biomarkers in plasma has developed significantly in recent years with technical improvements and evidence that they can be used in research,23, 24, 25and, even more recently, in clinical activity.24, 26The concentrations of β-amyloid peptide of 42aa and hyperphosphorylated tau protein, especially when phosphorylated in sites indicative of AD, such as p-tau217,25p-tau181, and p-tau231, can be used for research and also in clinical practice, although doubts still remain as to whether there is a need for confirmation with other biomarkers.27, 28. The gene discussed is MAPT; the disease is Alzheimer disease.