Additionally, lymphocyte populations present in the lung of pulmonary TB patients are Th1 (CD4+IFN-γ+CXCR3−), Th17 (CD4+IL-17A+CXCR3−), and Th1/Th17 (CD4+IFN-γ+IL-17A+CXCR3−). Here, IL17A is linked to pulmonary tuberculosis.