POSTN and allergic disease: In 2011, Corren et al. [20] reported that patients with high baseline serum periostin levels had more significant improvement in lung function with anti-IL-13 antibody (lebrikizumab) than did patients with low periostin levels, and the usefulness of periostin molecules as biomarkers or companion diagnostics of biologics for pulmonary and allergic diseases has been attractive.