TNF and rheumatoid arthritis: 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).