A targeting vector was generated to insert an IRES-NLS-cre cassette with an Frt-flanked PGK-neo sequence into the Noto locus, replacing exon 2, in G4 ES cells. Correctly targeted cells were used to produce founder chimeras that were crossed to CD1 (ICR) animals for germline transmission. Resulting animals were crossed to the Tg(ACTGLPe)9205Dym line to delete the PGK-neo.