FLT3 and acute myeloid leukemia: shRNA-mediated circMYBL2 knockdown specifically inhibited FLT3-ITD translation by preventing the binding of polypyrimidine tract-binding protein 1 (PTBP1) from FLT3 messenger RNA and impaired the cytoactivity of inhibitor-resistant FLT3-ITD AML, suggesting that circMYBL2 knockdown was effective against FLT3-ITD AML with quizartinib resistance [125].