A floxed neo cassette replaced 2.8 kb of upstream sequence between -1.3 kb and -4.1 kb from the initiation site. The neo cassette was removed by cre-mediated recombination following a cross to Tg(EIIa-cre)C5379Lmgd mice. Insertion was confirmed by PCR genotyping on embryonic stem cells. (J:125994)