For example, the disruptor of telomeric silencing 1-like (DOT1L) protein specifically mediates methylation of H3K79 and induces expression of downstream genes including homeobox A (HOXA) clusters (required for embryonic development) and MEIS1 (required for hematopoiesis) in MLL-r leukemia—an aggressive family of acute leukemia driven by rearrangement of the mixed lineage leukemia (MLL1) gene [45,46]. Here, KMT2A is linked to leukemia.