First of all, many human diseases are influenced by, if not caused by mutations in genes.

As I look back on the last few decades of my life, I am struck by the good fortune that came my way.

People are not the only interesting organism on earth. From the point of view of scientific or commercial value, there are lots of interesting organisms.

At every stage of my career I have had interesting and cordial colleagues, some of whom are close friends.

So I applied to medical school and received a scholarship at Washington University in St. Louis. Washington University turned out to be a lucky choice. The faculty was scholarly and dedicated and accessible to students.

My education began in the public schools of Wilmington. During most of these years, from about age 10, I also worked at some job or other after school, on weekends, and in the summer months.

The glimpses of human strength and frailty that a physician sees are with me still.