meaningful prognostic and treatment decisions. This system recognized differences in genetic, immunophenotype, molecular, and morphological features found through cytogenetic and molecular diagnostics tests. This subtyping helps determine the prognosis and the most appropriate treatment for each specific case of ALL. The WHO subtypes related to ALL are: B-lymphoblastic leukemia/lymphoma Not otherwise specified (NOS) with recurrent genetic abnormalities with t(9;22)(q34.1;q11.2);BCR-ABL1 with t(v;11q23.3);KMT2A rearranged with t(12;21)(p13.2;q22.1); ETV6-RUNX1 with t(5;14)(q31.1;q32.3) IL3-IGH with t(1;19)(q23;p13.3);TCF3-PBX1 with hyperdiploidy with hypodiploidy T-lymphoblastic leukemia/lymphoma Acute leukemias of ambiguous lineage Acute undifferentiated leukemia Mixed phenotype acute leukemia (MPAL) with t(9;22)(q34.1;q11.2); BCR–ABL1 MPAL with t(v;11q23.3); KMT2A rearranged MPAL, B/myeloid, NOS MPAL, T/myeloid, NOS Treatment The aim of treatment is to induce a lasting remission, defined as the absence of detectable cancer cells in the body (usually less than 5% blast cells in the bone marrow). Over the past several decades, there have been strides to increase the efficacy of treatment regimens, resulting in increased survival rates. Possible treatments for acute leukemia include chemotherapy, steroids, radiation therapy, intensive combined treatments (including bone marrow or stem cell transplants), targeted therapy, and/or growth factors. Chemotherapy Chemotherapy is the initial treatment of choice, and most people with ALL receive a combination of medications. There are no surgical options because of the body-wide distribution of the malignant cells. In general, cytotoxic chemotherapy for ALL combines multiple antileukemic drugs tailored to each person. Chemotherapy for ALL consists of three phases: remission induction, intensification, and maintenance therapy. Adult chemotherapy regimens mimic those of childhood ALL; however, are linked with a higher risk of disease relapse with chemotherapy alone. Two subtypes of ALL (B-cell ALL and T-cell ALL) require special considerations when it comes to selecting an appropriate treatment regimen in adults with ALL. B-cell ALL is often associated with cytogenetic abnormalities (specifically, t(8;14), t (2;8), and t(8;22)), which require aggressive therapy consisting of brief, high-intensity regimens. T-cell ALL responds to cyclophosphamide-containing agents the most. Radiation therapy Radiation therapy (or radiotherapy) is used on painful bony areas, in high disease burdens, or as part of the preparations for a bone marrow transplant (total body irradiation). In the past, physicians commonly utilized radiation in the form of whole-brain radiation for central nervous system prophylaxis, to prevent the occurrence and/or recurrence of leukemia in the brain. Recent studies showed that CNS chemotherapy provided results as favorable but with fewer developmental side effects. As a result, the use of whole-brain radiation