Do tumors have a shield?
One of cancer's great puzzles is how malignancies escape detection and destruction by the body's protective immune system. Cancer cells are known to carry distinctive surface proteins that should act as antigens, immunological alarms. Normally, the bodily defenses respond by alerting and marshaling antibodies, lymphocytes and macrophages, which attack the unwanted cells. But in the case of cancer, the attack is stifled or never gets under way.
Last week a husband-wife team at Boston's Massachusetts General Hospital and their colleagues offered a possible explanation that may also suggest...