CALGB, Cancer and Leukemia Group B; GRAAL, Group for Research on Adult Acute Lymphocytic Leukemia; GIMEMA, Gruppo Italiano Malatti EMatologiche dell'Adulto; GMALL, German Multicenter ALL; UD, unrelated donor; PETHEMA, Programa para el Estudio de la Terapéutica en Hemopatía Maligna; LAL, Spanish abbreviation for ALL; PALG, Polish Acute Leukemia Group; GRAAPH, Group for Research in Adult Acute Lymphoblastic Leukemia; Ph+, Philadelphia positive; GRAALLPHAG, Group for research on Philadelphia positive ALL.