APL is unique among leukemias due to its sensitivity to all-trans retinoic acid (ATRA; tretinoin), the acid form of vitamin A.[1] Treatment with ATRA dissociates the NCOR-HDACL complex from RAR and allows DNA transcription and differentiation of the immature leukemic promyelocytes into mature granulocytes by targeting the oncogenic transcription factor and its aberrant action.[1] Unlike other chemotherapies, ATRA does not directly kill the malignant cells.[1] ATRA induces the terminal differentiation of the leukemic promyelocytes, after which these differentiated malignant cells undergo spontaneous apoptosis on their own. ATRA alone is capable of inducing remission but it is short-lived in the absence of concurrent "traditional" chemotherapy.[1] As of 2013 the standard of treatment for concurrent chemotherapy has become Arsenic trioxide,[7] before 2013 the standard of treatment was anthracycline (e.g.daunorubicin, doxorubicin, idarubicin or mitoxantrone)-based chemotherapy. Both chemotherapies result in a clinical remission in approximately 90% of patients with arsenic trioxide having a more favorable side effect profile.[4]