According to the vector molecular image presented by the International Knockout Mouse Consortium, this allele has one FRT site, an engrailed 2 splice acceptor sequence, an EGFP and cre/ERT2 expression cassette, a Rox-flanked puromycin resistance cassette followed by one loxP site all inserted into the intron just upstream of exon 4, and a single loxP site just downstream of exon 4. (J:188991)