Pathway analysis revealed that the genes down-regulated upon siRNA knockdown of HOXC4 and/or HOXC6 (i.e. genes whose expression is positively regulated by the TFs in the control 22Rv1 cells) are related to cancer and cell cycle (Fig 1C); these categories were not observed for the set of up-regulated genes. This evidence concerns the gene HOXC6 and cancer.