TNF and rheumatoid arthritis: Significant progress has been made in the last few decades in both the early diagnosis and treatment of patients with RA.1, 2, 3, 4, 5 In particular the development of biological drugs that target molecules linked with the propagation of arthritic inflammation, including tumour necrosis factor (TNF) and interleukin (IL)-6, has transformed the management of patients with this otherwise debilitating condition.