MAPT and chronic kidney disease: Renal function may influence plasma p‐tau levels, although studies have reported mixed results regarding the association between chronic kidney disease (CKD), lower estimated glomerular filtration rates (eGFRs), and higher p‐tau181, p‐tau217, and unphosphorylated tau concentrations55, 56 Similarly, the relationship between body mass index (BMI) and p‐tau levels remains unclear, with some findings suggesting an inverse association, possibly due to a dilutional effect.57