Considering that stem cell properties have been linked with tumor malignancy [14, 26, 27], together with our microarray data implicating the HOXA9 transcriptome in typical hallmarks of cancer (Supplementary Figure 3, Supplementary Figure 10 and Supplementary Table 1), we hypothesized that HOXA9 could play a role in tumor growth in vivo. This evidence concerns the gene HOXA9 and cancer.