Abstract
Leukemia can be acute or chronic, derive from different types of cells, and arise by different mechanisms, most of which are still unknown. One unique form — adult T-cell leukemia–lymphoma — though rare in many geographic regions, is common in others. It is perhaps the most thoroughly studied type of leukemia. We know more about its distribution, cause, and pathogenesis than we do about those of other leukemias,16 but paradoxically, it remains one of the most difficult cancers to treat.4 Two reports in this issue of the Journal may herald a change in that situation.7,8 In 1977 Takatsuki . . .