Many of us think of cancer as a contemporary killer, a disease of our own making caused by our modern lifestyles. But, as Kat Arney explains in her new book REBEL CELL: Cancer Evolution and the Science of Life, that perception just isn’t true. Although it might be rare in many species, cancer is the enemy lurking within almost every living creature. Why? Because cancer is a bug in the system of life. We get cancer because we can't not get it.

Cancer has always been with us. It killed our hominid ancestors, the mammals they evolved from and the dinosaurs that trampled the ground before that. Tumours grow in pets, livestock and wild animals. Even tiny jelly-like Hydra - creatures that are little more than a tube full of water - can get cancer.

Cancer starts when cells rebel against the social norms of the body, throwing off their molecular shackles and growing out of control in a shambolic mockery of normal life. This is why we can't avoid cancer: because the very genes that drive it are essential for life itself.