Rheumatoid arthritis (RA) is a typical auto-immune disorder, characterized by an increase in pro-inflammatory cytokines (including TNF-α, IL-6, and IL-1β) and inducible inflammation-related enzymes (such as cyclooxygenase and lipoxygenase) and a decrease in anti-inflammatory cytokines (as IL-4 and IL-10). This evidence concerns the gene IL4 and rheumatoid arthritis.