Although CDK4/6i+ATRA did not significantly enhance myeloid differentiation or induce irreversible cell growth arrest (Supplementary Fig. 3), it preferentially triggered apoptotic cell death in the human acute monoblastic and monocytic leukemia cell lines, MV4-11, MOLM-13, and MOLM-14 (classified as M5 in the FAB classification [18]) (Supplementary Figs. 4 and 5a–c). The gene discussed is CDK4; the disease is monocytic leukemia.