What makes cancer cells different from ordinary cells? Can these differences be used to strike at them and paralyze their activity? This basic question has bothered cancer researchers since the mid-19th century. The search for unique characteristics of cancer cells is a building block of modern cancer research. A new study led by researchers from Tel Aviv University shows, for the first time, how an abnormal number of chromosomes (aneuploidy) could become a weak point for these cells. The study could lead to the future development of drugs exploiting this vulnerability to eliminate the cancer cells.