Many cytokines are involved in chronic lower respiratory tract inflammatory diseases such as asthma, including interleukin (IL)-4, IL-5, IL-6, IL-9, IL-12, IL-13, granulocyte colony stimulating factor (G-CSF), granulocyte-macrophage colony stimulating factor (GM-CSF), and interferon (IFN)-γ, all of which activate JAK/STAT signaling [6,7,8]. The gene discussed is CSF2; the disease is asthma.