ABSTRACT
The body must defend itself against potential harm, both from the outside environment around us, and from the inside environment within us. Chapter 2 identified a wide range of outside agents that can cause damage to DNA (see p. 48), and as such they are capable of inflicting health-destroying changes to our cells, like the mutations listed in Chapter 2 (see p. 38). If cellular DNA is damaged the cell could become malignant (see p. 24), and the body must defend itself against abnormal cells like these. The defence strategy of the body is known as immunity.
