ZFN- and TALEN -mediated HDR to correct the mutations at endogenous CFTR loci in CF patient-derived iPSCs (Crane et al., 2015; Fleischer et al., 2020) and TALEN-mediated site-specific integration of a CFTR minigene at the AAVS1 safe harbor (Xia et al., 2019) are the examples of using these tools in the research for CF gene therapy. Here, CFTR is linked to cystic fibrosis.