A guanine to adenine at position 3925 (ATC>GTC) and adenine at position 3977 instead of guanine (CGT>CAT) were introduced in exon 28 to create the I1309V and R1325H mutations. In addition, a floxed pGK-Neo cassette was inserted downstream of exon 28 which was removed via cre-mediated excision. (J:220792)