For Mark Lewis, MD, cancer has defined his entire life. Growing up, he witnessed his father's valiant struggle with cancer before it eventually ended his life. While still in medical training, he not only developed pancreatic cancer but also discovered the culprit. Multiple endocrine neoplasia type 1, an inherited syndrome that drastically increases one's risk of cancers, runs in his family. So now, as a father, he guides his son in making sense of a life burdened with that risk. What’s more,...