Administration of the immunosuppressant methotrexate (MTX) in combination with infliximab or adalimumab has been found to reduce ADA formation and results in a decrease in the incidence of secondary failure (12, 13), but since many elderly RA patients, especially in Asia, including in Japan, are unable to tolerate MTX (14), a new anti-TNFα antibody with low immunogenicity is needed for the treatment of RA. The gene discussed is TNF; the disease is rheumatoid arthritis.