A team of researchers at Case Western Reserve University School of Medicine have identified a new mechanism by which colon cancer develops. By focusing on segments of DNA located between genes, or so-called ‘junk DNA,’ the team has discovered a set of master switches called gene enhancer elements, that turn ‘on and off’ key genes whose altered expression results in colon cancer. They have coined the term Variant Enhancer Loci or VELs, to describe these master switches. Importantly, VELs are not mutations in the actual DNA sequence, but rather are changes in proteins that bind to DNA, a type of alteration known as ‘epigenetic’ or ‘epimutations.’ This is a critical finding because such epimutations are potentially reversible.Over the course of three years, the team mapped the locations of hundreds of thousands of gene enhancer elements in DNA from normal and cancerous colon tissues, pinpointing key target VELs that differed between the two types.