A transgene construct was produced in which a modified human Angiopoietin 1 cDNA (COMP-Ang1) was separated from the CAG promoter by a loxP-blasticidineS cDNA-polyA-loxP sequence. The construct was injected into TT2 ES cells. A cre-expressing plasmid was introduced into the transfected ES cells and 2 clones demonstrated high levels of COMP-Ang1 expression. Transgenic mice were generated from clone 5. When crossed to a suitable cre-expressing line, the offspring will express the modified form of human angiopoietin 1. (J:147388)