The gene trap vector was found to have integrated within intron 3. It consists of the inverted repeat direct repeat sequence specific for sleeping beauty transposase flanking human BCL2 splice acceptor sequence, IRES, lacZ, poly A signal, a chimeric CAG promoter containing sequence from the chicken ACTB promoter, GFP, and splice donor sequence. This allele was generated from mice carrying TgTn(sb-lacZ,GFP)IF2Jtak and Tg(CAG-sb10)1Jtak.