In the CNS, IL-22BP expression is upregulated in the cerebral spinal fluid (CSF) of patients with active MS (Perriard et al., 2015) and mice deficient in the expression of IL-22BP show less severe disease in a mouse model of EAE (Laaksonen et al., 2014), while increased IL-22BP expression correlates with greater macrophage infiltration and more severe neuroinflammation in a rat EAE model. This evidence concerns the gene IL22RA2 and myeloid sarcoma.