The idea that cancer genes are sitting inside each and every one of our chromosomes, just waiting to be corrupted or inactivated and thereby unleashing cancer, is, of course, one of the seminal ideas of oncology.

It turns out that the very genes that turn on in cancer cells perform vital functions in normal cells. In other words, the very genes that allow our embryos to grow or our brains to grow, our bodies to grow, if you mutate them, if you distort them, then you unleash cancer.

One day, I had a patient who was going through chemotherapy who came to me and said, 'I'm going to go on with what I'm doing, but I need you to tell me what it is that I'm fighting.'

Siddhartha Mukherjee Quotes