BPIFA1 and chronic rhinosinusitis: The antimicrobial effect of PLUNC and its surfactant activity of lowering the surface tension of the airways mucosa may represent a novel form of innate immunity that limits bacterial colonization of the airways; a dysfunction of the innate immune system may play a permissive role in chronic rhinosinusitis pathogenesis, creating an environment that fosters increased microbial colonization [9].