CFTR and asthma: Although CFTR is expressed at a lower level in other airway epithelial cell subtypes, in particular secretory cells, the highest expression of CFTR was in ionocytes from both healthy and asthma donors (Figure 3A), which also validated the reduced but remaining residual CFTR function in hBECs from patients with non‐eosinophilic asthma (Figure 1A).