The increase of cytokines such as IL-12 and IFN-γ play a determinant role in the complex cascade of events leading to the imbalance toward a detrimental Th1 environment in MS (21): IL-12 p40 mRNA level in unstimulated MNC increases in MS patients compared with controls (22) whilst MS patients experiencing a relapse have significantly increased IFN-γ production after mitogen-driven MNC stimulation compared to patients in remission, which is reduced after treatment with IFN-β (23). The gene discussed is IFNB1; the disease is myeloid sarcoma.