Most discoveries even today are a combination of serendipity and of searching.

I wanted to explore cancer not just biologically, but metaphorically. The idea that tuberculosis in the 19th century possessed the same kind of frightening and decaying quality was very interesting to me, and it seemed that one could explore the idea that every age defined its own illness.

This was yet another colonial fascination: to create the conditions of misery in a population, then subject it to social or medical experimentation.

It remains an astonishing, disturbing fact that in America - a nation where nearly every new drug is subjected to rigorous scrutiny as a potential carcinogen, and even the bare hint of a substance's link to cancer ignites a firestorm of public hysteria and media anxiety - one of the most potent and common carcinogens known to humans can be freely bought and sold at every corner store for a few dollars.

In 2005, a man diagnosed with multiple myeloma asked me if he would be alive to watch his daughter graduate from high school in a few months. In 2009, bound to a wheelchair, he watched his daughter graduate from college. The wheelchair had nothing to do with his cancer. The man had fallen down while coaching his youngest son's baseball team.

All cancers are alike but they are alike in a unique way.

A breast cancer might turn out to have a close resemblance to a gastric cancer. And this kind of reorganization of cancer in terms of its internal genetic anatomy has really changed the way we treat and approach cancer in general.