MCL1 and acute myeloid leukemia: In acute myeloid leukaemia (AML) cell lines (HL-60, OCI-AML-3 and MV4-11) and the acute promyeloid leukaemia cell line NB-4, compound 9 presents concentration-dependent inhibition of CDK9 phosphorylation through downregulation of RNA polymerase II, Mcl-1 and c-Myc.