PML and acute promyelocytic leukemia: The first targeted therapy of AML used all-trans retinoic acid (ATRA) targeting to PML-RARA fusion of Acute Promyelocytic Leukemia (APL), a subtype of AML characterized by the translocation of the retinoic acid receptor α (RARA) on chromosome 17 and promyelocytic leukemia (PML) gene on chromosome 153.