The histone-lysine N-methyltransferase 2A (KMT2A; also known as mixed-lineage leukemia 1 [MLL1])-fusion proteins require direct interaction with the nuclear scaffolding protein menin in order to form menin-KMT2A complex, which plays a key role in the transcription of multiple leukemogenic target genes. On the basis of this, it is hypothesized that blocking the menin-KMT2A interaction by small-molecule inhibitors could be a promising new strategy for the treatment of KMT2A-altered and NPM1-mutant acute myeloid leukemia (AML).