There are a number of biological components involved in the process of ageing. These cause the body to slowly degrade at the cellular level. Old age is also a leading risk factor for many common illnesses, such as cancer and heart disease. Tackling ageing, therefore, is seen as a way to combat many diseases at once. This is the motivation behind Google’s anti-ageing startup called Calico, which was founded last year and is led by Art Levinson, the former head of Genentech, a pioneer of the biotechnology industry.