In animal models, imiquimod stimulates the innate immune response by increasing NK cell activity, activating macrophages to secretecytokines and nitric oxide, and inducing proliferation and differentiation of B lymphocytes. Imiquimod stimulates the innate immune response through induction, synthesis, and release of cytokines, including interferon-a (IFN-α), interleukin (IL)-6, and tumour necrosis factor (TNF)-α.