The Promyelocytic Leukemia protein (PML) was first recognized in Acute Promyelocytic Leukemia (APL) where it is translationally fused to the retinoic acid receptor α (RARA) as a consequence of the t (15;17) chromosomal translocation (de The et al., 1990; Kakizuka et al., 1991). This evidence concerns the gene RARA and acute promyelocytic leukemia.