Sporadic CRC develops through the accumulation of genetic and epigenetic alterations in the epithelial cell-lining. These alterations are thought to push the normal epithelial cells into the adenoma-carcinoma sequence. Detection of hypermethylated DNA can be made in blood or stool of cancer patients and it is believed, that hypermethylated cell-free DNA in blood and stool can be used as a cancer biomarker, exhibiting high sensitivity and specificity in CRC and other major cancer-types (e.g. lung, prostate, and breast cancer).