Genetic factors such as polymorphisms can stimulate or retard the production of specific cytokines.6Previous studies have indicated pro- or anti-inflammatory polymorphisms in cytokine genes such as tumor necrosis factor-α and interleukin 1β (IL-1β),7IL-6,8transforming growth factor-β,9IL-10,10, 11and interferon-gamma (IFNg),12, 13also concerning periodontitis. This evidence concerns the gene IFNG and periodontitis.