Despite the clear role for IL-10 in limiting the severity of EAE (7, 8), and its association with reduced white matter lesions and an improved Expanded Disability Status Scale (EDSS) score in MS (63, 76), relatively less is known about the impact of its cognate receptor IL-10Rα in regulating neuroinflammation. This evidence concerns the gene IL10RA and myeloid sarcoma.