In vivo, Nur77 is expressed aberrantly in inflammatory diseases, such as lung cancer, atherosclerotic lesions, multiple sclerosis, and inflamed human synovial tissue (2, 9, 35), and Nur77 knockout mice are more susceptible to a variety of diseases, including sepsis, airway inflammatory diseases, atherosclerosis, colitis, inflammatory bowel diseases, and cerebral ischemia, all of which can be attributed to an enhanced inflammatory response (24, 36, 40, 41). This evidence concerns the gene NR4A1 and inflammatory bowel disease.