TLR4 and Behcet disease: Pathogens such as herpes simplex virus, streptococci, staphylococci, or Escherichia species, and heat- shock proteins may contribute to attacks of BD in susceptible persons via stimulation of the innate immune system (inflammasome activation) through TLR2 and TLR4 [14–16], In addition, because OU is often the presenting symptom of BD, the composition of the oral mucosa and salivary microbiome is thought to be one trigger of disease flares [17].