POSTN and asthma: However, contradictory evidences exist: Gordon et al. [11] explored the biological role of periostin in asthma using a mouse model and periostin deficient mice and, surprisingly, found that periostin deficient mice have increased AHR and markedly increased serum IgE levels following repeated intranasal challenge with Aspergillus fumigatus antigen, compared to wild-type mice controls.