CFTR and cystic fibrosis: LCI is an early marker of ventilation inhomogeneity, reflecting initial airways dysfunction in CF population with normal pulmonary function tests [9–10] and it is being recognized as a useful surrogate pulmonary outcome measure, especially in the new era of CFTR modulators, where new disease trajectories will require adequate clinical markers to characterize clinical phenotypes and monitor the efficacy of treatments [11–14].