We know cancer is caused ultimately via a link between the environment and genes. There are genes inside cells that tell cells to grow and the same genes tell cells to stop growing. When you deregulate these genes, you unleash cancer. Now, what disrupts these genes? Mutations.

I think the cardinal rule of learning to write is learning to read first. I learned to write by learning to read.

The history is important because science is a discipline deeply immersed in history. In other words, every time you perform an experiment in science or in medicine, what you're actually doing is you're answering someone, answering a question raised by someone in the past.

Writing anything as an expert is really poisonous to the writing process, because you lose the quality of discovery.

People may say I developed an iron will, but what really happened is that I made myself much fitter. I think an iron will is always supported by fitness.

That's the worst health condition you can have, not being alive.

Like most, I've had an on again, off again relationship with fitness, sometimes beginning every day at the gym only to forget about my membership for months at a time.

The nature of Ebola is that health-care workers are predominantly affected because of the way that it is spread.