ATO can rapidly degrade PML‐RARα fusion protein and induce the apoptosis of APL cells, thereby relieving the repression of genes targeted by PML‐RARα.39 In our study, we observed different changes in LMO2 expression upon ATRA or ATO treatment in NB4 cells (Figure S1A and B). Here, RARA is linked to acute promyelocytic leukemia.