Investigations of the CSF of euthymic BD patients and healthy controls show increased levels of monocyte chemoattractant protein-1 [MCP-1] and chitinase-3-like protein 1 [YKL-40] (Jakobsson et al. 2015), as well as elevated levels of IL-8 and IL-1β (Isgren et al. 2015; Soderlund et al. 2011) in BD. Here, CHI3L1 is linked to Behcet disease.