High serum levels of pro-inflammatory cytokines [IL-1, IL-6, IL-12, interferon γ (IFN-γ), and transforming growth factor-β] and chemokines (CCL2, CXCL9, CXCL10, and IL-8) were found in patients with SARS with severe disease compared with individuals with uncomplicated SARS (31). Here, CXCL9 is linked to severe acute respiratory syndrome.