CHIT1 and proximal spinal muscular atrophy: Andrés-Benito et al. reported that CHIT1 expression was upregulated in microglia and macrophages within the spinal cord of SMA patients, and that CSF levels of CHIT1 were associated with disease severity and progression in adult SMA type 2 and 3, suggesting a role in SMA-related neuroinflammation [65].