External inflammatory stimulation leads to the activation of TLR4, which induces the phosphorylation of NF-κB and the release of IL-1β, IL-6, TNF-α to induce the immune response and inflammation, which may also be an important mechanism by which TLR4 is involved in the pathogenesis of PF (44, 45). The gene discussed is IL1B; the disease is pemphigus foliaceus.