CXCL9 and infection: Multifunctional Th17 cells (IFN-γ+IL-17A+) co-expressing CXCR3/CCR6 are known to upregulate the ligands for CXCR3 (CXCL9/CXCL10/CXCL11) on the lung parenchymal cells, which helps to recruit Th1 cells to the site of infection [17, 18].