Adalimumab (Humira) is a tumour necrosis factor α (TNFα) inhibitor that is approved for the treatment of rheumatoid arthritis, psoriasis, psoriatic arthritis, Crohn's disease, ankylosing spondylitis, and juvenile idiopathic arthritis (Sullivan and Preda (2009), Klinkhoff (2004), and Medicare Australia). The gene discussed is TNF; the disease is psoriatic arthritis.