The promyelocytic leukemia tumor suppressor gene (PML) was initially identified as a component of the PML-Retinoic Acid Receptor Alpha (RARA) oncoprotein as a result of the chromosomal translocation t(15;17) of acute promyelocytic leukemia (APL) (de The et al., 1990; Goddard et al., 1991; Kakizuka et al., 1991; Pandolfi et al., 1991). Here, PML is linked to acute promyelocytic leukemia.