POSTN and asthma: Song et al. found significantly higher periostin values in children with asthma compared with healthy children (76 [65–91.8] vs. 71 [57.5–80] ng ml–1), and a relationship between levels of serum periostin and response to mannitol and methacholine.[72] These authors detected significant correlation between serum periostin, blood eosinophil count and FeNO.