Distribution of DNA methylation levels of different genomic components in MCF-7/S0.5 versus TAMRcell lines. MCF-7/S0.5 shows low DNA methylation levels compared with TAMR cell lines in both the global profile and the different genomic components (CpG island (CGI), CGI shore, gene, promoter and exon). The x axis shows the color-coded methylation states of CpGs for the MCF-7/S0.5, TAMR-1, TAMR-4, TAMR-7 and TAMR-8 cell lines. The mean methylation state of CpGs is categorized into very high (grey, 0 to 1 tag), high (blue, 2 to 10 tags), intermediate (orange, 11 to 100 tags), and low (yellow >100 tags). The y axis shows the proportion of CpGs covered by methylation scores at low, intermediate, or high levels. Coordinates for genomic features were taken from the University of California, Santa Cruz genome database, with the exception of CGI shores, which were defined as 2 kb on either side of the CGI.