Your body is made up of tiny building blocks called cells. Inside every cell is a set of genes. They are the instructions the cell needs to work properly. Genes control:
- how a cell does its job in the body
- when it divides to make new cells
- the cell’s death when it is not needed any more.
Sometimes the structure inside a gene is permanently changed, so the gene no longer gives the correct instructions. This change is called a gene mutation.
Some cells in your body develop gene mutations during your lifetime. These are called acquired mutations. It is also possible to have a gene mutation because it passed from one of your parents to you. This is called an inherited mutation.
Eventually, gene mutations in a cell may mean the cell stops working normally. Cancer develops when cells like this can multiply in an abnormal way and grow out of control.