IFNG and Nasal polyposis: Staphylococcal protein A (SpA), a virulence factor from S. aureus, coupled to immunoglobulins in immune complexes, induces IL-10 production and suppresses staphylococcal enterotoxin B-induced IL-5, IL-13, IFN-γ and IL-17 production by nasal polyp cells [117].