Cre mediated recombination removed a floxed 70 kb region corresponding to the human 9p21 non-coding coronary artery disease risk interval. The 5' targeting vector contained a 5' homologous region and loxP site upstream of a neo cassette while the 3' targeting vector contained a copy of the 3' homologous region and hygro cassette upstream of a loxP site. Reduced expression of Cdkn2a and Cdkn2b was confirmed by qRT-PCR on heart and other tissue extracts. (J:158126)