The difference in event-free survival (EFS) for younger patients and ALK-positive ALCL treated with cyclophosphamide, hydroxydaunomycin, oncovin, and prednisone (CHOP) or cyclophosphamide, doxorubicin, etoposide, vincristine and prednisone (CHOEP) within trials is dramatic (three-year EFS for CHOEP patients was 91.2% vs. 57.1% for patients treated with CHOP, P=0.012). This evidence concerns the gene ALK and anaplastic large cell lymphoma.