Within the adaptive immune system, there is some evidence that CD4+ Th1, Th2, and Th17 subtypes may play role in pulmonary fibrosis and their plethora of cytokines such as interferon gamma (IFN-γ) for Th1 and IL-4 and IL-13 for Th2 cells have been linked to disease development in the lung (Wynn, 2011). The gene discussed is IFNG; the disease is pulmonary fibrosis.