Thus, while the detection of TH17 or TH17.1 cells themselves cannot be used as specific markers of sarcoidosis outcome, the presence of TH17/TH17.1 cells along with elevated levels of TGF-β1, IFN-γ, or IL-17A may prove to be a valuable indicator of disease severity and progression. The gene discussed is IL17A; the disease is sarcoidosis.