The transgene contains the CAG promoter (CMV-IE enhancer, chicken beta-actin promoter, rabbit beta-globin genomic DNA), phage P1 loxP sites, E. coli chloramphenicol acetyltransferase (CAT) gene, poly A, signal peptide, myc-tag, Delta1 cDNA. Cre-mediated recombination is required to achieve expression of Dll1. (J:104881)