Variability in Clinical Performance of the FDA-Cleared Lumipulse P-Tau217/β-Amyloid 1-42 Plasma Ratio. - Algeciras-Schimnich A; Bornhorst JA; Figdore DJ; Rea Reyes RE; Ashrafzadeh-Kian S; Wilson R; Burkett BJ; Johnson DR; Botha H; McCarter SJ; Day GS; Graff-Radford J; et al. (JAMA neurology, 2026)