Barschke et al. reported increased CSF levels of NFM and CHIT1 in patients with C9ORF72-ALS, possibly reflecting neuroinflammation and neurodegeneration.50 In addition, these researchers showed that CHI3L2 CSF levels were increased in C9ORF72-ALS but not in C9ORF72-FTD, suggesting potentially different roles of microglia in the pathophysiology of these diseases. The gene discussed is CHIT1; the disease is amyotrophic lateral sclerosis.