Exon 43 was replaced with one in which nucleotide substitutions result in the amino acid substitution of serine with leucine at position 2245 in the encoded peptide (p.S2245L), mimicking a mutation found in some catecholaminergic polymorphic ventricular tachycardia patients. The floxed neomycin resistance gene cassette that was inserted into intron 43 was removed by cre-mediated recombination. (J:186291)