"I don't think there will ever be a cure for cancer."
This was the opening line by Alfred Knudson, Jr, MD, PhD, the 1998 Lasker Award recipient, as he lectured at our medical school.

He had just been introduced by our director of cancer research who ended with the high-flying statement "... and some day we may see a cure for cancer."

Knudson went on to say, "Cancer is the natural consequence of cooking DNA in an aqueous solution at body temperature over a lifetime." This follows from his discovery that a two-hit mutation causes retinoblastoma, confirming the hypothesis that cancer is the result of accumulated mutations to a cell's DNA.

Sitting in the lecture hall with my other white-coated colleagues, ready to begin clinical rotations, I was  impressed by this one-upmanship, but even more so later on when I realized what an elegant and memorable explanation this was.

It's a challenge to come up metaphors as good as that one for phenomena occurring on the molecular level such as "apoptosis." Talking or writing about medical science in an easy-to-understand way forces you to go back many times to make sure your explanation gives a fair sense of the current model.You also don't want to fall into the trap of presenting an overly cheery view of the future that is merely a platitude. Someone might come along and deliver the real goods.