A specific and successful differentiation therapy using ATRA and arsen trioxide was established for a small subset of patients carrying the oncogenic PML-RARα fusion protein apparent in APL.17,46 As the classical chemotherapeutics exhibit high toxicity and side effects and did not undergo striking changes in the past decades, it is highly important to identify further therapeutics addressing the leukemia cell maturation. This evidence concerns the gene RARA and acute promyelocytic leukemia.