Relationship between DNA methylation and gene expression in MCF-7/S0.5 and TAMR1. An inverse relationship between DNA methylation and gene expression levels is noted. The expressed genes are grouped according to expression levels: low (left), moderate (middle) and high (right). Dark blue, light blue, orange and yellow present extreme-high, high, medium and low DNA methylation levels. The x axis shows the genomic location relative to the transcriptional start site. The y axis shows the percentage of methylation for a given genomic location.