NEFL and amyotrophic lateral sclerosis: The pooled mean sensitivity, specificity, and hierarchical summary receiver-operating characteristic curve of CSF NfL in distinguishing ALS patients from controls were 0.91 (95% CI, 0.86 to 0.94), 0.90 (95% CI, 0.83 to 0.94), and 0.95, respectively (I2 = 83.7%; Figure 2A).