POSTN and asthma: 32 bronchial epithelial samples from asthma patients were classified as Th2-high asthma group according to the expression of three signature genes (SERPINB2, POSTN, and CLCA1) of type 2 inflammation using Euclidean distance clustering analysis, and the remaining 19 samples were assigned to the Th2-low asthma group (Figure 7A).