PML and acute promyelocytic leukemia: promyelocytic leukemia protein (PML) was initially identified in the acute promyelocytic leukemia (APL), a disease largely associated with t(15, 17) chromosomal translocation, which results in the fusion protein of PML and the retinoic acid receptor alpha (RARα) (de The et al., 1991; Goddard et al., 1991; Kakizuka et al., 1991; Pandolfi et al., 1991).