The adaptive immune response is initiated by activating T cells, which are stimulated by antigen-presenting cells, including dendritic cells.72 In periodontitis, T helper 1 (Th1), Th2, and Th17 cells are key players in the immune response.73 Th1 cells, driven by the transcription factor T-bet and induced by IL-12, produce interferon-gamma (IFN-γ), which activates macrophages and promotes a pro-inflammatory response. The gene discussed is IFNG; the disease is periodontitis.