Mixed-lineage leukemia is a cancer type characterized by a segment of chromosome 11 breaking off and attaching to another chromosome. This form of leukemia in children is associated with a particularly poor prognosis. Its name reflects the unique gene expression patterns that are different from those seen in acute lymphoblastic leukemia (ALL) and other forms. Patients often exhibit very high white blood cell counts and frequent organ involvement. Standard treatments for ALL are typically ineffective, and there is a high risk of early relapse after treatment. The mixed-lineage leukemia gene is located at 11q23, and translocations in this region can occur in up to 80% of infants diagnosed with acute leukemia within their first six months. The incidence decreases between six months and a year, though it remains noteworthy. As children grow and into adulthood, the frequency further declines but can still be found in 3% to 4% of adults with acute myeloid leukemia (AML) and ALL. Detecting this translocation often requires advanced analytic methods beyond standard chromosome analysis. Mixed-lineage leukemia is considered a separate entity and not a subtype of ALL, necessitating distinct therapeutic approaches.