Another selective inhibitor of DOT1L, SYC-522, an S-adenosyl-L-methionine (SAM) derivative, blocks the cell cycle at the G0/G1 phase and sensitizes MLL-r leukemia cells to chemotherapeutic agents (mitoxantrone, etoposide, and cytarabine), causing apoptosis. Here, DOT1L is linked to leukemia.