The gene promoter region and cg23866403 DNA methylation loci were observed to be in close proximity to the enhancer of the FXYD1 gene in the normal sample, as compared to the longer distance between the regulatory elements in breast cancer, where FXYD1 gene is down-regulated and cg23866403 loci are hyper-methylated, as shown in the box plots (Figure 7A(ii)). The gene discussed is FXYD1; the disease is breast cancer.