The gene that enables birds to learn songs can become cancer-causing. There is no normal physiological process that can't be bastardized by the disease.

If you take 100 breast-cancer samples, 100 types of cancer have 100 different hallmarks of mutated genes. You could be nihilistic and say, 'Oh, God, we'll never be able to tackle this!' But there are deep, systematic, organizational principles at work in all that diversity.

Because I work on leukemia, the image of cancer I carry in my mind is that of blood. I imagine that doctors who work on breast cancer or pancreatic cancer have very different visualizations.

Siddhartha Mukherjee Quotes