A new study reports how an experimental drug agent stops cancer cells from growing. A little over a decade ago, scientists first reported pentagamavumon-1 (PGV-1), an analogue of a molecule found in turmeric and that has been since discovered to have anti-cancer effects. In the new study, tests on cancer cells and animals reveal that these anti-cancer effects come from PGV-1 inhibiting a series of enzymes responsible for the metabolism of reactive oxygen species. This finding is expected to clarify how modifications to PGV-1 will lead to its use for cancer treatment.