We measured ROS and MPO production in peripheral neutrophils under spontaneous or PMA-stimulated conditions by the Amplex Red assay and found that the levels of ROS and MPO were significantly increased in neutrophils when stimulated with PMA (Figures 3(a) and 3(b)) and that IBD neutrophils produced more ROS and MPO compared to healthy controls. The gene discussed is MPO; the disease is inflammatory bowel disease.