CXCL12 and amyotrophic lateral sclerosis: In amyotrophic lateral sclerosis cases, the relationship between CXCL12 and NF-L levels in CSF and plasma was also assessed, but no significant correlations were observed (Pearson r = 0.08784, P = 0.5754; and Spearman r = −0.1093, P = 0.5195, respectively).