CLCA1 and atopic asthma: In a study of 84 US adults, including 42 individuals with atopic asthma, 21 individuals without atopic asthma, and 21 atopic healthy individuals acting as controls, investigators used the bronchial epithelial gene expression levels of 3 genes, CLCA1, SERPINB2, and POSTN, to calculate a type 2 score for asthma (60).