RARA and acute promyelocytic leukemia: To evaluate the in vitro therapeutic potential of our solubilized realgar product, we tested its ability to induce degradation of PML in NB‐4 cells, an APL cell line expressing PML/RARalpha.[34] The results showed that solubilized realgar was able to deplete PML at submicromolar concentrations at 72 h post‐treatment (Figure4A).