Therefore, CDK9 inhibitors (such as dinaciclib and CDKI-73) exert antitumor effects in preclinical models of MLL-rearranged acute leukemia.71,72 2) Myeloid cell leukemia 1 (MCL-1) is upregulated in AML and is essential for AML development and growth.73,74 However, short-lived MCL-1 requires P-TEFb to maintain its high expression to promote leukemia cell survival. Here, MCL1 is linked to leukemia.