This animation shows how tumors use the protein VEGF to recruit blood vessels.

VEGF (vascular endothelial growth factor) is a cell signaling protein that stimulates blood vessel growth. Cancer cells can develop a blood supply that supports their growth by releasing VEGF, which stimulates blood vessels to grow toward them.

This animation is a clip from a 2003 Holiday Lecture Series, Learning From Patients: The Science of Medicine. Depending on students’ background, it may be helpful to pause the animation at various points to discuss different features.