HGF and viral infectious disease: In addition, it has been demonstrated that inflammatory cytokines, such as oncostatin M (OSM), hepatocyte growth factor (HGF), interferon-γ (IFN-γ) [58], and toll-like receptors 7 and 8 (TLR7/8), when stimulated by viral infections, can trigger KSHV reactivation (reviewed in [59]).