Cancer is an uncontrolled growth of body tissue anywhere in a person’s body. This growth interferes with the way your body normally functions. There are many kinds of cells that make up the tissue in a human body. Cells make new cells by dividing. Some cells stop dividing when you become an adult. Other cells constantly divide, such as those of your skin, hair and blood. Some divide only if there has been damage somewhere in your body. They “turn on” only until the damage has been repaired. Cancer tissues have lost their ability to “turn off” their growth. They eventually crowd out healthy tissues, disrupting your body’s ability to do what it needs to do.