Requirement for circMYBL2 in FLT3-ITD AML cells. (A) Efficient knockdown of circMYBL2 in MOLM-13 cells. (B) Specific si-circMYBL2 did not influence parental gene expression. (C) Effect of circMYBL2 knockdown on proliferation in FLT3-ITD⁺ cells. (D-E) Flow cytometric analysis of cell-cycle progression in AML cells. The numbers indicate the percentages of cells. (F-G) Flow cytometric analysis of apoptosis. The numbers indicate the percentages of cells. (H) Flow cytometric analysis of apoptosis in primary AML patient cells including FLT3-ITD AML patient cells (#1 and #2), and FLT3-ITD^– patient cells (#4). 7AAD, 7-Aminoactinomycin D; sub-G1, sub cell cycle gap 1 phase.