A transgene consisting of hs1753 (chr7:158,888,320-158,891,362) enhancer element located in intron 4 of human VIPR2 gene subcloned into Hsp68 promoter fused with ERT2CreERT2-pA to drive expression of cre in response to tamoxifen in developing heart. A total of nine transgenic founders lines 1, 17, 20, 22, 23, 29, 30, 32, 33 were obtained. All transgenic lines showed heart-specific cre activity when bred to a cre reporter mouse.