Cancer is one of the leading causes of death in the present world. It affects various organs of the body ranging from the stomach, uterus, bladder e.t.c Cancer is basically the uncontrolled multiplication of cells of your body despite the action of growth signals. So normally new cells generate and die eventually but in cancer the cells are " selfish" hence they don't die. They also undergo transformations meaning they are not like your normal body cells and therefore they are foreign like. That is why cancer is so hard to treat especially if you are in the later stages. I'm putting a few articles on cancer so you understand it better. Have a blast