Interestingly, a study on ovarian cancer cell line and normal tissue showed that DNA methylation of some of the analyzed genes, including Hoxa9, Hoxa10, MiR-34b, Prom1, Cables1, Sparc, and Rsk4, had an inverse correlation with their expression level (Niskakoski et al., 2014). This evidence concerns the gene HOXA9 and ovarian cancer.