Pulitzer Prize-winning author Matt Richtel discusses how the immune system affects us in life and death.Our immune system impacts every aspect of our lives, including sleep, mood, fitness, nutrition, brain function and aging. And yet, it's widely misunderstood. In his book, An Elegant Defense, Pulitzer Prize-winning author Matt Richtel discusses how the immune system affects us in life and death. Tune in to hear the inspiring story of how immunotherapy helped one cancer patient shrink a 15-pound tumor and dodge death. Plus, hear the latest scientific research on this critical part of our health and wellness. Bonus Study Suggests Eggs Raise Risk of Heart Disease and Early Death