A single injection of special proteins can make cancerous tumours regress, claim David A Cheresh and Peter C Brooks from the Scripps Research Institute, San Diego. They found that the injected proteins which are either synthetic or genetically engineered block the blood vessels that feed the tumour, causing them to shrink.

The scientists performed the experiments by grafting fragments of a variety of human cancers onto mice, rabbits and chicken embryos. Human clinical trials are expected to start in about 18 months. This technique also could provide a new therapy for many eye disorders, including damages that result from diabetes.