When an oncogene is damaged, it is like the accelerator of your car is glued to the floor. Abnormal cells divide recklessly. Tumor suppressor genes tell cells when to stop dividing. When tumor suppressor genes become disabled, they act like a faulty brake on a car, unable to stop runaway cell division. Normally, as new cells grow, old cells die to make way for them, a process called apoptosis.
All cells are programmed to die at a certain time - it is nature's own planned obsolescence.
If cells divide when new ones are not called for or do not die according to schedule, they can form a mass of excess tissue called a tumor. The cells in malignant tumors can invade and damage nearby tissues and organs. They can also break away from the malignant tumor and spread through the bloodstream or lymphatic system to create more tumors in other parts of the body. All rights reserved.