NEFL and Alzheimer disease: Among the AD-related BBMs, p-Tau181 exhibited the strongest correlation with CL values (r = 0.54, p<0.0001), followed by GFAP (r = 0.48, p<0.0001), Aβ42/40 (r = -0.48, p<0.0001) and NfL (r = 0.27, p<0.0001).