Since mTOR signaling could promote Th1 and Th17 cell differentiation and inhibit Treg commitment through different mTOR complexes, we anticipate a disadvantageous effect of mTOR signaling on periodontal diseases though regulating CD4+ T cell subsets, though the influence of mTOR signaling on Th22 and Th9 is not clear yet. The gene discussed is CD4; the disease is periodontal disorder.