However, enzymatically dead versions of DOT1L are unable to rescue DOT1L deficiencies in MLL-FP leukemias [263] and DOT1L enzymatic inhibitors have little effect on other leukemias [261], suggesting that whatever the specific role is, H3K79Me2 is key for maintaining the expression of MLL-FP target genes. The gene discussed is DOT1L; the disease is leukemia.