Exon 34 was replaced with a modified one in which nucleotide substitutions (ATC to GCC) result in the amino acid substitution of alanine for isoleucine at position 1169 (I1169A) and a V5 epitope tag. This mutation abolishes the PCNA-binding site. Cre-mediated recombination removed a floxed splice acceptor, IRES and beta-geo cassette inserted upstream of the modified exon 34. (J:202812)