Good response in RA to MTX treatment is followed by few processes, such as induction of apoptosis in T cells or monocyte/macrophage cells, inhibition of the production of proinflammatory cytokines (IL-1 and IL-6), stimulation of the production of anti-inflammatory cytokines (IL-4 and IL-10), and inhibition of metalloproteinases production [12]. This evidence concerns the gene IL6 and rheumatoid arthritis.