Figure 5. Candidate functional SNPs are association with SMAD7 gene expression levels.

Fold change (FC) of SMAD7 expression was measured in normal colon tissue samples from surveillance colonoscopies. Rank-based non-parametric analysis was used to estimate the effect of each extra minor allele for rs6507874, rs6507875, rs8085824, and rs4939827 (additive model) on gene expression adjusting for gender, age and race. Two-sided p-values were obtained from a likelihood ratio test. Log₂(ΔΔCt) were plotted as a function of genotypes using a box plot – dot plot overlay. Number of samples is noted under each genotype. A statistically significant association was found for rs8085824.