Within the ColoCare Project we obtained genome-wide DNA methylation profiles from 149 mucosa and 112 colorectal cancer tissues using Illumina HumanMethylation450k BeadChips. DNA methylation profiles were analysed by patient characteristics, lifestyle and exposures. Overall design: Colorectal cancer patients were recruited at the University Hospital of Heidelberg. Genomic DNA from 149 mucosa and 112 tumor samples were analyzed, including 105 tumor-mucosa pairs. For one patient 3 replicates coming from different chips were included.