AFF1 and acute lymphoblastic leukemia: In contrast to other forms of ALL, these patients are characterized by a frequent presence of disseminated intravascular coagulation (DIC) at diagnosis: Vey and collaborators have described 14 cases of DIC in 34 patients with t(4;11)(q21;q23)/MLL-AF4 positive ALL at diagnosis (41%), a percentage significantly higher compared to other patients enrolled in the LALA-94 cooperative study of the France-Belgium Group for Lymphoblastic Acute Leukemia in Adults.