Although chromosome instability has long been proposed to promote tumor progression, recent studies suggest that chromosome instability can either promote or suppress tumor progression.[1] The difference between the two are related to the amount of chromosomal instability taking place, as a small rate of chromosomal instability leads to tumor progression, or in other words cancer, while a large rate of chromosomal instability is often lethal to cancer.[9] This is due to the fact that a large rate of chromosomal instability is detrimental to the survival mechanisms of the cell,[9] and the cancer cell cannot replicate and dies (apoptosis). Therefore, the relationship between chromosomal instability and cancer can also be used to assist with diagnosis of malignant vs. benign tumors.[9]