Considering the Th1/Th2 paradigm of leprosy, the cytokine profile found in the skin differs at each pole, with a higher expression of Th1 cytokines (such as IL-7 and IL-15) in people with tuberculoid leprosy and higher expression of Th2 cytokines (such as IL-4, IL-5, IL-10 and transforming growth factor-beta [TGF-β]) in patients with lepromatous leprosy. The gene discussed is IL4; the disease is leprosy.