It has been shown that serum periostin in combination with blood eosinophils and basophils count has the potential to discriminate eosinophilic nasal polyps and non-eosinophilic nasal polyps [57] and, in combination with IgE and Staphylococcal enterotoxin (SE)-IgE, may be useful to identify nasal polyps with moderate and severe type 2 inflammation [58]. This evidence concerns the gene POSTN and Nasal polyposis.