Studies have demonstrated that repeated allergic asthma during pregnancy can alter the expression of cytokines in the fetal environment, including interferon-γ (IFN-γ), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin 1α (IL-1α), interleukin IL-6, and tumor necrosis factor α (TNF-α). The gene discussed is TNF; the disease is allergic asthma.