HOX genes with significant differences between human AAA and control human abdominal aorta assayed by microarrays. Box-and-whisker plots of mRNA levels for the 10 classic HOX genes that had significantly (FDR <0.05) different expression levels between AAA cases (N = 6) and age-, sex-, and ethnicity-matched controls (N = 7) obtained from abdominal aorta. Results are based on microarray expression profiling which have been described previously  and details on the donors are described in Additional file 2, Table S2. RNA expression levels in signal intensity units are indicated on the ordinate-axis. Thick horizontal bars in the boxes indicate median values, boxes indicate interquartile range, whiskers indicate range of non-outlier values, and circles indicate outliers less than 3 interquartile range units. Gene symbols available from the National Center for Biotechnology Information (NCBI; http://www.ncbi.nlm.nih.gov/) were used. For a full list of all HOX genes and their expression levels in human aorta, see Additional file 5, Table S4.