CFTR and cystic fibrosis: The efficacy of this gene-correction strategy has been verified in intestinal organoids and airway epithelial cells derived from patients with CF, who carry the mutations of c.1679 + 1.6kbA>G (1811 + 1.6kbA>G), or c.3140–26A>G (3272-26A>G) or c.3717 + 12191C>T (3,849 + 10kbC>T), with an allele-specific repair efficiency of ∼40% and complete functional recovery of the CFTR channel (Sanz et al., 2017; Maule et al., 2019).