Until 2021, several LSD1 inhibitors including irreversible inhibitors tranylcypromine (TCP), ORY-2001, ORY-1001, GSK-2879552, INCB059872, IMG-7289, TAK-418, and reversible inhibitors CC-90011 and SP-2577 have entered clinical evaluation as mono- or combined therapy for diseases, particularly for AML and small lung cancer cells (SCLC). The gene discussed is KDM1A; the disease is acute myeloid leukemia.