HGF and influenza: Indeed, prior studies have documented those patients with severe influenza, e.g., those hospitalized in ICU, have significantly elevated levels of numerous cytokines and chemokines, including IL-6, IL-10, IL-15, CXCL10 (IP-10), soluble IL-2 receptor (sIL-2R), hepatocyte growth factor (HGF), ST2, and CXCL9 (MIG), compared to patients with mild influenza [32].