I left Delhi in 1989 and remember very little of how life used to be then. Increasingly, in my recent visits to Delhi, I've started to realize that the city has become intellectually very lively. It makes me want to discover the city over and over again.

In the laboratory, we call this the six-degrees-of-separation-from-cancer rule: you can ask any biological question, no matter how seemingly distant-what makes the heart fail, or why worms age, or even how birds learn songs-and you will end up, in fewer than six genetic steps, connecting with a proto-oncogene or tumor suppressor.

I think the way we think about cancer, the way we treat cancer, has dramatically changed in the last century. There is an enormous amount of options that a physician can provide today, right down from curing patients, treating patients or providing patients with psychic solace or pain relief.

Most days, I go home and I feel rejuvenated. I feel ebullient.

Sandeep Jauhar’s Doctored is a passionate and necessary book that asks difficult questions about the future of medicine. The narrative is gripping, and the writing is marvelous. But it was the gravity of the problem—so movingly told—that grabbed and kept my attention throughout this remarkable work.

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

If there's a seminal discovery in oncology in the last 20 years, it's that idea that cancer genes are often mutated versions of normal genes.