Last week on the Ó³»´«Ã½ website, we featured recent work by Ó³»´«Ã½ researchers that can shed new light on the massive genomic changes taking place in cancer cells. The genomes in tumors are often drastically disorganized, with large chunks of missing or extra DNA — even whole chromosomes — in addition to smaller, single-letter mutations. These alterations can complicate the search for genetic changes underlying cancer.