MAPT and Alzheimer disease: Benussi et al. (2025) demonstrated in a large clinical cohort that plasma p-tau217 levels effectively distinguished AD from frontotemporal lobar degeneration (FTLD). The p-tau 217/neurofilament light chain (NfL) ratio further refined the diagnosis. Their three-tiered plasma biomarker framework significantly diminished dependence on cerebrospinal fluid (CSF) analysis by more than 50%, highlighting the practicality of blood-based diagnostics for regular clinical application (Benussi et al., 2025).