Acute promyelocytic leukemia, commonly called APL, is a malignancy of the bone marrow in which there is a deficiency of mature blood cells in the myeloid line of cells and an excess of immature cells

Acute promyelocytic leukemia is a subtype of acute myelogenous leukemia (AML), a cancer of the blood and bone marrow. It is also known as acute progranulocytic leukemia.