NFKB1 and rectal cancer: Any SNP identified as significantly associated with colon and rectal cancer in the first step was then analyzed in 2-locus haplotypes with all other markers within IKBKB, IL6, and NFKB1. We did not observe any informative haplotypes within IKBKB or IL6 using hapConstructor that were associated with colon cancer beyond the single SNP results, nor in rectal cancer.