Tumor necrosis factor (TNF-α, or TNF) is a major mediator of apoptosis as well as inflammation and immunity, and it has been implicated in the pathogenesis of a wide spectrum of human diseases such as diabetes, cancer, osteoporosis, multiple sclerosis, rheumatoid arthritis, acute shock, and inflammatory bowel disease (IBD) [1]. The gene discussed is TNF; the disease is rheumatoid arthritis.