This allele was generated by breeding mice homozygous for Cd3etm1Lov with transgenic mice expressing cre recombinase via the EIIa promoter, resulting in the excision of the floxed neo. Northern blot analysis of homozygous mutant mice showed normal levels of Cd3d and Cd3g transcript as well as the presence of a truncated Cd3e transcript. Sequencing of Cd3e cDNA derived from RT-PCR analysis showed the splicing of exons 4 to 7 (lacking the extracellular and transmembrane domains). Western blot analysis showed the absence of truncated protein product.