Two different orchestras play the same score of damage, but their conductors are different: one brakes before division, the other before DNA duplication. Oral cancer and breast cancer receive the same neutron strike, yet respond differently. One cell line freezes on the threshold of division, the other on the threshold of copying genetic material. The outcome is the same—cell death—but the path to it differs.

The scientists took two types of cancer cells and irradiated them with neutrons after the cells had accumulated boron. After irradiation, the oral cancer cells showed nearly twice as many DNA breaks as the breast cancer cells. But the main difference lay in the cell cycle—the conveyor belt along which a cell moves from birth to division. The oral cancer cells got stuck right before division, while the breast cancer cells stalled earlier, before DNA duplication.

As a result, the cells died in different ways. The oral cancer cells almost completely lost their ability to reproduce, whereas the breast cancer cells more often triggered the self-destruct mechanism, yet nearly half of them retained the ability to produce offspring. Previously, it was unclear why this happens: whether it is due to the amount of boron or to the cells themselves. Now it is clear that both factors matter. Therefore, clinicians planning such treatment should look not only at how much boron the tumor has accumulated, but also at its molecular portrait. Two orchestras play the same score, but their conductors are different—and to predict how each will perform, you need to know both.