Since the discovery that TNF-α plays a determining role in the pathogenesis of several chronic inflammatory diseases, anti-TNF agents are increasingly being used in the treatment of a rapidly expanding number of rheumatic and systemic autoimmune diseases, such as rheumatoid arthritis, Crohn's disease, psoriasis, psoriatic arthritis, ankyloting spondylitis, Wegener granulomatosis and sarcoidosis.
This approach proved to be fruitful in both sarcoidosis and Wegener granulomatosis, suggesting that stratification of data by clinical phenotypes may discover genetic associations that analysis of disease susceptibility alone would fail to detect.