Additionally, in autoimmune brain diseases such as neuromyelitis optica (NMO), Chi3l1 reportedly impairs hippocampal neurogenesis and cognitive function, whereas blocking the Chi3l1/CRTH2/β-catenin cascade contributes to restoring neurogenesis and improving cognitive deficits (Figure 2) [202]. This evidence concerns the gene CHI3L1 and neuromyelitis optica.