CFTR and cystic fibrosis: Founder animals were bred with WT rabbits to verify germline transmission, and 3 lines of CF rabbits were established carrying the following insertion or deletion (indel) types: (a) CFΔ1, with 1 nucleotide deletion (Δ1) that generates a premature stop codon after amino acid 477; (b) CF+1, with 1 nucleotide insertion (+1) that generates a premature stop codon after amino acid 480; and (c) CFΔ9, with a 9-nucleotide deletion (Δ9) that results in deletion of amino acids P477, S478, and E479 (Supplemental Figure 1, A–C).