Interestingly, while no unique phosphorylation site on soluble tau has been identified as exclusively indicative of AD, the presence of phosphorylation at T217, T231, and S396 within the soluble tau fraction serves as a potential biomarker to distinguish AD patients from non-AD individuals (Kyalu Ngoie Zola et al., 2023). This evidence concerns the gene MAPT and Alzheimer disease.