TNF and periodontitis: The expressions of OCN, RUNX‐2, TNF‐α and COX‐2 were quantified through immunohistochemical assays and the findings (Figure 3B) indicated markedly enhanced TNF‐α and COX‐2 protein levels in the periodontal tissue with periodontitis in the model group, and the MSCs and IL‐10‐MSCs treatments were able to downregulate the levels of TNF‐α and COX‐2, inversely having more OCN and RUNX‐2 positive cells than the model group.