We used TALENs and CRISPR-Cas9 to target two different sites of the CFTR gene: (1) to introduce the most common CF mutation, ΔF508, and (2) to correct the rare nonsense mutation, W1282X, for CF modelling in human embryonic stem cells (hESCs) [36] and three patient-derived induced pluripotent stem cells (iPSCs) [37], respectively. Here, CFTR is linked to cystic fibrosis.