Patients with relapsing multiple sclerosis (RR-MS) under IFN-β treatment were found to have significantly increased levels of both NKG2D, an activating receptor on the surfaces of NK cells, and interleukin-22 (IL-22), suggesting that IFN-β treatment directs NK cells toward a pro-inflammatory state [84]. This evidence concerns the gene IL22 and myeloid sarcoma.