RARA and acute myeloid leukemia: Several tyrosine kinase inhibitors (TKIs), such as FLT3 inhibitors (sorafenib and midostaurin) and BCR-ABL inhibitors (imatinib and nilotinib), and PML/RARα inhibitors (all-trans retinoic acid and arsenic trioxide) have been developed and clinically applied to patients with AML and CML as single agents or in combination with chemotherapy [7,8,9,10].