This result may be explained by the fact that periodontal pathogens, such as Porphyromonas gingivalis, participate in the activation of B lymphocytes and plasma cells to secrete specific IgG, IgA, and IgM antibodies that are involved in periodontitis pathogenesis (Seymour et al., 1983; Zouali, 2017). The gene discussed is CD40LG; the disease is periodontitis.