CDKN2B and coronary artery disorder: However, the most strongly associated SNPs lie considerably upstream of these genes, and the nearest signal is 10 kb upstream of CDKN2B. The C-allele of the lead SNP (rs1333049) has a frequency of 0.17 in Yoruba, 0.48 in Han Chinese, 0.51 in Japanese and 0.49 in Europeans indicating that the risk of CAD and MI related to the chromosome 9p21 locus may vary among different ethnic groups.