The presence of periodontitis could increase the number of T and B cells in gingival tissue and blood of T2D patients, B cells could further induce osteoclast differentiation, and the proinflammatory cytokine profile secreted by B cells of periodontitis patients was similar to that of T2D patients, such as TNF-α and IL-1β, which could promote periodontitis and diabetes (20, 40). The gene discussed is TNF; the disease is periodontitis.