Exon 3 was replaced in-frame by the coding sequence for EGFP followed by a PGK-neomycin cassette. RT-PCR analysis indicated that exon 2 spliced to exon 4 in transcripts thus skipping exon 3 entirely. This results in a frame shift and a premature stop codon in exon 5. Western blot analysis using antibody specific to C-terminal sequences indicated the absence of gene product.