No association has been demonstrated between CSF and plasma CXCL12 levels and ALS-FRS-R scores, unlike the correlation seen with NF-L levels in CSF and plasma, as previously has been observed.23,24 In consequence, more studies involving larger cohorts of patients and exploration of other mimic conditions are necessary to validate and strengthen our findings. The gene discussed is NEFL; the disease is amyotrophic lateral sclerosis.