KRT23 and asthma: The 8 genes consistently differentially expressed in severe asthma compared to health across both airways exhibited consistent fold changes and included genes involved in cytoskeletal structure regulation, cell proliferation and differentiation, such as keratin 23 (KRT23), fibroblast growth factor binding protein 1 (FGFBP1) and a chemokine receptor type 7 (CXCR7) (S3 Table).