A new study published in the journal Nature Medicine shows that phosphorylated tau (p-tau) in the blood, previously used to diagnose Alzheimer's disease, could also serve as a biomarker for other types of systemic amyloidosis.[1] The research was conducted as a multicenter cross-sectional study and found that serum p-tau could help diagnose the most common forms of systemic amyloidosis.[1] The biomarker could also be useful in differentiating amyloidosis-related polyneuropathy from polyneuropathy due to other causes.[1] These findings suggest that p-tau has the potential to be a more versatile diagnostic tool than previously thought and may expand its use beyond the diagnosis of Alzheimer's disease.[1]