Sheldon Cohen 
The Slim Book of Health Pearls: Man the Barricades — The Story of the Immune System [EPUB ebook] 

The immune system is a complicated mechanism whose principle actors are organs, cells, chemicals and a vast collection of proteins tuned by billions of years of evolution to work in a harmonious manner for the good of the whole. Its purpose is to keep us alive in a world where visible and invisible predators intending to usurp our bodies attack us on a daily basis. By virtue of an amazing communication network, millions of cells gather, exchange information, become activated and respond to bacteria, fungi, parasites and viruses preventing them from causing infection. A malfunctioning immune system, when immune cells attack ‘self, ‘ results in numerous auto-immune diseases, the ‘God only knows’ diseases of sixty years ago.