The ability of tumor cells to form tubular networks that mimic blood vessels can help drive metastasis, the spread of breast cancer to different sites in the body, a mouse model study has demonstrated. The researchers are now examining what it takes for tumor cells that have exited from a primary tumor into the bloodstream to then get out of the bloodstream and colonize a new site in the body. “We’ve identified some interesting targets that we think seem to be key for this step,” researcher says.