The roles of cytokines, such as IFN-γ, TNF-α, IL-1β and IL-6, expressed in inflammatory diseases such as multiple sclerosis are complex (Merrill & Benveniste, 1996; Sharief, 1998; Minagar & Alexander, 2003; Imitola et al., 2005). The gene discussed is TNF; the disease is multiple sclerosis.