Promyelocytic leukemia protein (PML) was originally found in patients with a rare subtype of acute myeloid leukemia (AML) called acute promyelocytic leukemia (APL), which expresses a PML–RARα fusion oncoprotein encoded by PML and the retinoic acid receptor alpha (RARα) chromosomal translocation between chromosomes 15 and 17, t(15;17) [52–55]. The gene discussed is PML; the disease is acute myeloid leukemia.