tumor blood vessels

Tumors require a blood supply to grow, but how this supply is acquired remains poorly understood. A study published in PLoS ONE shows that tumor blood vessels can develop from precancerous stem cells, a recently discovered type of cell that can either remain benign or become malignant.

Researchers say the findings provide new information about how tumors develop blood vessels, and why drugs designed to block tumor blood-vessel growth are often less effective than expected.