A vector was designed to delete a part of exon 9 and all of exon 10, which encode the basic, glutamine-rich and SAP domains. A lacZ was fused in frame with exon 9 and a neo cassette. RT-PCR demonstrated that the correct exons were deleted and that exon 8 was spliced to exon 12, thereby deleting the lacZ-neo cassette. The resulting truncated protein would be nonfunctional.