The most significantly associated haplotype was found in the IL1 cluster (CCC haplotype, frequency of 41% in the total sample), which was found at increased frequency in all CAD cases (P = 0.006), MI cases (P = 0.01) and young CAD cases (P = 0.0002), although the overall haplotype effect only reached the 5% significance level in early-onset CAD cases (P = 0.02, with 7 degrees of freedom). Here, IL1A is linked to coronary artery disorder.