POSTN and asthma: Th2-high asthma has three specific differentially expressed transcriptomic profiles, namely, periostin (POSTN), chloride channel regulator 1 (CLCA1), and serpin peptidase inhibitor, clade B, member 2 (SERPINB2), among which POSTN was found to be a more reliable surrogate marker for Th2-high asthma [7,8].