M3, or Acute Promyelocytic Leukemia (APL), comprises about 10% of all AML cases and features the PML-RARα fusion protein from the t(15;17) translocation, with a favorable prognosis due to effective treatments with all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) [11,12,13,14]. This evidence concerns the gene RARA and acute promyelocytic leukemia.