One thing cells must do in order to become cancerous is to overthrow the normal checks on their growth. As a part of this process, the stringent controls on things like copying and repairing DNA start to break down. As a result, tumors often contain chromosomal rearrangements, which are places where genes are cut and pasted back together in ways that they shouldn’t be.
In some cases, the breaks bring two genes together in a way that causes what are called “driver mutations,” forming a fusion protein that pushes the cells further along the road to malignancy. For some types of cancer, nearly every tumor contains one of these chromosome breaks, making its fusion genes a hallmark of that cancer.… Read the rest