Figure 2. The serum neurofilament light chain (sNfL) and cerebrospinal fluid NfL (cNfL) levels and associations between NfL levels and the revised El Escorial criteria grade. The sNfL and cNfL levels were highly correlated (A). The sNfL level was significantly higher in patients with definite or probable amyotrophic lateral sclerosis (ALS) than in patients with possible or probable laboratory-supported ALS according to the revised El Escorial criteria (B). The cNfL level was not different between the two groups (C). Translucent bands indicate 95% CIs.