Do you want to live a long healthy life? Do you want a great health span? Dr. Lewis unravels the mysteries of our immune system and explains that it and its strength - not your genetics - is the only thing that help you achieve your longevity goals. The problem this book solves is three-fold: 1. How to measure the strength of your immune system, 2. How to determine if your health and longevity is under even the slightest attack - by measuring low-grade chronic inflammation, and 3. How to improve your immune system strength and increase your health span.