It is widely used in vitro to stimulate cells to form an inflammatory environment.26 In a short period after Pg-LPS stimulation, DPCs secrete abundant inflammatory factors, such as IL-6, IL-8, and IL-1β, and the CCL2 chemokine.27 IL-1β is highly produced in inflammatory pulp tissue; however, there is controversy on whether IL-1β is expressed after LPS stimulation of DPCs.28 IL-6 and IL-8 are key elements involved in inflammation and their expression in the pulpitis region is high. The gene discussed is CCL2; the disease is pulpitis.