IBSP and chronic rhinosinusitis without nasal polyps: Our study has shown upregulated bone-homeostasis genes—human bone sialoprotein gene IBSP (generally upregulated), extracellular phospoglycoprotein MEPE, and interferon-induced transmembrane protein 5 IFITM5 (both upregulated only in CRSsNP), which may play a potential role in viral infection [28,29].