Human KRT14 gene-targeting vector. The AAV vector used for targeting the human KRT14 gene is shown above a graphic of the genomic locus. Exons are depicted as black boxes and numbered, with introns indicated by adjoining lines. The IRES-GFP or IRES-neo expression cassettes are shown and areas of sequence homology are indicated by thin adjoining lines. The insertion site for the expression cassettes within exon 3 is also shown. A, synthetic polyadenylation signal; AAV, adeno-associated virus; GFP, green fluorescent protein; IRES, internal ribosomal entry site from encephalomyocarditis virus; TR, terminal repeats.