Acute lymphoblastic leukemia (ALL) is the most diagnosed childhood cancer worldwide. Although rare in adults, this aggressive cancer also shows a second smaller incidence peak in later middle age.Modern genetic profiling techniques are providing a better understanding of the molecular biology of ALL, which, in turn, is leading to significant advances in diagnosis, prognostication and therapy selection. Ongoing refinement of risk-adapted frontline treatment protocols, use of novel targeted therapies and better supportive care are improving outcomes for patients with ALL.Fast Facts: Acute Lymphoblastic Leukemia covers the epidemiology, etiology, diagnosis and classification of ALL as well as the measurement of minimal residual disease to determine prognosis. It provides guidance on frontline therapies and the treatment of relapsed and refractory ALL, including the use of newer targeted agents and the role of allogeneic stem-cell transplantation. Looking to the future, it also considers the approaches and refinements that are in development for ALL.Table of Contents: Epidemiology, pathophysiology and etiology Diagnosis Prognostic factors Treatment Relapsed or refractory ALL Future directions