CFTR and cystic fibrosis: In addition, iPSC-derived airway organoids have been used for studying cystic fibrosis, a disease caused by mutations in CFTR. iPSCs derived from patients with cystic fibrosis due to homozygous ΔF508 mutations were used for evaluating CFTR-dependent organoid swelling in response to forskolin,6 a CFTR activator.