Although except for MLL-rearranged leukemia, the molecular mechanisms that link LSD1 to these malignancies are not fully understood (likely because LSD1 has multiple protein substrates), inhibition of LSD1 generally caused broad gene expression pattern changes in these sensitive tumors, which could be responsible for the anti-proliferative activity and other effects, e.g., inducing apoptosis and/or differentiation. Here, KMT2A is linked to leukemia.