In the fight against cancer, finding its causes are just as important as finding the cure. Epidemiologist Dr. Devra Davis
explains why she thinks the war on cancer has been very misguided, and needs to change. Also: find out what scientists can learn from glowing jellyfish and fireflies. Jim Shepherd
shares his new short story collection. And we hear about the life and tragic death of a Guatemalan human rights activist.
Friday's Please Explain is about laughter. To help us prepare, tell us something that always makes you laugh. Is it a joke? a person? a situation? Leave a comment here.