PML and acute promyelocytic leukemia: The promyelocytic leukemia zinc finger protein (PLZF), firstly discovered as part of the fusion protein with retinoic acid receptor-α (RARα) in acute promyelocytic leukemia (APL) [27], belongs to the family of Kruppel-type zinc finger proteins and contains a conserved POZ protein-binding domain at its N-terminal.