How Science Works.

Do White Blood Cells Make Cancer Deadly?: Scientific American: "The issue contained a letter from three Czech doctors asking whether the fusion of tumor cells and white blood cells could cause cancers to spread, or metastasize. At the time, Pawelek was also reading a book by evolutionary biologist Lynn Margulis, who pioneered the idea that life on earth was revolutionized by ancient cells engulfing one another and fusing together, forming hybrids that had better chances at survival. “I was really excited by the connection,” he recalls. “Since there was a precedent for hybridization in evolution, why not in cancer?”"

J'C: The article goes on to describe Pawelek's 15 year investigation of this hypothesis and starting with mice and finally moving on to human studies. It looks like he is on the verge of some important information on the mechanism of metastasis.