NCI has initiated a hospital-based case-control study of lymphoma in Eastern Asia of 3,300 cases and 3,300 controls, known as AsiaLymph. The major postulated risk factors for evaluation in this study are chemical exposures (i.e., organochlorines, trichloroethylene and benzene), genetic susceptibility, and infectious agents. Investigators will confirm and extend previous findings and hope to yield novel insights into the causes of lymphoma in both Asia and the West.