Oncologist and Professor of Medicine at Columbia University, Dr. Siddhartha Mukherjee, a Pulitzer Prize winner in non-fiction for his book, "The Emperor of All Maladies," explores medicine and the radical new ability to manipulate cells in his new book, "The Song of the Cell."Gastroenterologist Dr. Shilpa Ravella shares a riveting investigation of inflammation―the hidden force at the heart of modern disease―and how we can prevent, treat and even reverse it. Her book is, "A Silent Fire."