The BBC reports that researchers have discovered an enzyme that they say is crucial in allowing cancer to metastasize. Metastasization is responsible for 90 percent of cancer deaths, so stopping the spread of the disease would be by far the largest step to improving treatment. (The story does not state what the prognosis is for a drug that would block the enzyme in humans, although it references studies in mice, without saying whether the enzyme was effectively blocked.)
One downside: the enzyme in question is LOX. Does that mean no more bagels....?