SET and acute lymphoblastic leukemia: The location of the MLL gene is where chromosomal translocations in AML and ALL usually occur.389 When the MLL gene is translocated, the catalytic SET domain is lost, which results in MLL translocation-generated fusion proteins, which recruit DOT1L.390 Maintenance of MLL-associated ALL depends on the methylation of H3K79 catalyzed by DOT1L.391 Therefore, DOT1L is usually associated with hematological malignancies rather than solid tumors.