Excessive superoxide anion (O2−) production and raised ADA activity (a marker of activated neutrophil function, chemotaxis, and phagocytosis), as well as hydrogen peroxide- (H2O2-) induced hydroxyl radical (OH) and malondialdehyde productions have been demonstrated in BD patients, suggesting neutrophil-mediated immunity and increased amount of reactive oxygen species (ROS) production, especially in the exacerbation period [23]. This evidence concerns the gene ADA and Behcet disease.