In fact, A. actinomycetemcomitans-induced periodontitis in IFN-γ-knockout mice resulted in decreased alveolar bone resorption accompanied by an impaired host defense against microbial dissemination followed by mice death, showing the key role of the Th1-related type-I IFN signaling in the local immune-mediated pathological bone loss and host protective response against A. actinomycetemcomitans (52). This evidence concerns the gene IFNG and periodontitis.