This is the intriguing argument made by a pair of researchers from Johns Hopkins University. In a study published Friday in the journal Science, they found a very high correlation between the differences in risk for 31 kinds of cancer and the frequency with which different types of stem cells made copies of themselves.
Just how strong was this link? On a scale that goes from 0 (absolutely no correlation) to 1 (exact correlation), biostatistician Cristian Tomasetti and cancer geneticist Bert Vogelstein calculated that it was at least a 0.8. When it comes to cancer, that's high.