A leading scientist's spirited, confident guide to the way our immune system protects us-most of the time

Humans may be the most disease-ridden animals on the planet. Our immune system is all that stands between us and hordes of opportunistic bacteria, viruses, and parasites, and scientists have been investigating its breathtaking complexity for over a hundred years. But there is still much to discover, and new breakthroughs continue to emerge.

Leading immunologist John Trowsdale shows how the immune system works tirelessly to protect us against noxious pathogens and is even involved in conditions such as dementia, cardiovascular disease, obesity, and cancer. Its functions are largely hidden to us, but our bodies invest extensive resources to keep it running. And sometimes, in exceptional cases, our own organs and tissues can get caught in the crossfire in the fight against disease.

This is a remarkable account of a fascinating phenomenon-one whose importance is only becoming more evident as we face multiple epidemics and health crises.