Gene expression helps classify cancers

Only about 60 percent of people with diffuse large B-cell lymphoma, a common cancer of white blood cells, respond well to therapy. This cancer, as currently defined, is in fact two distinct diseases, according to new tests that use so-called gene chips to look at the activity of thousands of genes simultaneously. Patients with one pattern of gene expression, called germinal-center B-like pattern, seem to respond better to treatment than the other patients do, says R.