KDM1A and acute myeloid leukemia: Interestingly, it was reported that the combined effect of RA and LSD1 siRNA had a synergistic effect on promoting the apoptosis of neuroblastoma cells [52], and that also combined treatment with all-trans retinoic acid (ATRA), which is the major occurring retinoic acid, and GSK2879552, an LSD1 specific inhibitor, resulted in synergistic effects on enhancing markers of differentiation and promoting cytotoxicity in acute myeloid leukemia across subtypes [53].