PML and acute promyelocytic leukemia: As expected, we found that the expression of NEAT1 was increased by PML-RARα knockdown (Figure 2B).Because APL treatment leads to the clearance of leukemia cells and loss of PML-RARα transcripts, we next investigated the expression of NEAT1 and PML-RARα in NB4 cells before and after ATRA treatment (1 μM, stock: 10 mM in EtOH) to further establish the relationship between NEAT1 and PML-RARα.