Imiquimod is an imidazoquinoline derivative. Some studies have shown that imiquimod modulates the Th1/Th2 response by inducing the production of Th1 cytokines IFN-γ and interleukin (IL)-12,1 and by inhibiting Th2 cytokines IL-4 and IL-5. These data suggest that imiquimod has therapeutic applications in atopic diseases such as allergic asthma that are associated with overexpression of Th2 cytokines.