Many new cancer treatments are designed to block the development of new blood vessels that feed tumors. One of the most common targets is the vascular endothelial derived growth factor (VEGF). New research has shed light on the mechanism by which anti-VEGF treatments cause the death of endothelial cells, the precursors to blood vessels. The treatments cause an increase in a protein calle Bim. Bim is able to cause apoptosis, a form of cellular suicide. The discovery opens up the possibility of new treatments to increase the activity of Bim in cancer cells.