Dividing colorectal cancer cells. Animated coloured scanning electron micrograph (SEM) of a sequence of colorectal cells undergoing mitosis (nuclear division). From a single cell (top left) to identical daughter cells (bottom right). Without the process of mitosis there would be no cancer. Cancerous cells ignore or override some of the control measures of this type of cell division. Cancer and mitosis are closely related. Mitosis is the process by which cells reproduce, and without it cancerous cells wouldn't be able to form tumors and spread through the body. Globally, colorectal cancer is the third most common type of cancer making up about 10% of all cases.