As summarized in Figure 11, our previous studies [36,38] and our present study have shown that periodontitis-associated LPS and MetS-associated SFA, such as PA, synergistically stimulate ASMase, leading to increased production of ceramide in macrophages and subsequent upregulation of inflammatory cytokines such as IL-6 and IL-1b. The gene discussed is SMPD1; the disease is metabolic syndrome.