Credit: MPI for Heart and Lung Research
This is a diagram of the mechanism by which metastatic cancer cells exit blood vessels. The APP molecule on cancer cells activates the DR6 receptor on vascular wall cells (endothelial cells). As a result, the endothelial cell is selectively killed (through a process called necroptosis). In this way, the cancer cell creates an escape route from the bloodstream. It then either slips directly through the resulting gap (1) or interferes with chemical messengers from neighboring cells around the dead endothelial cell, causing a gap to form between them (2)