Cancer cells have a ticket to ride

Spreading cancer cells have learned a thing or two from their nemesis, the immune system. Just like the immune system’s white blood cells, or leukocytes, cancer cells rely on the process known as leukocyte trafficking to migrate through the body, according to a report in the Feb. 28 Nature by cancer researchers at Schering-Plough/DNAX Research Institute in Palo Alto, Calif.