RARA and acute promyelocytic leukemia: 55 ATO exerts dose-dependent dual effects on APL cells: at low concentrations (0.5 μM), ATO induces partial differentiation by degrading the PML/RAR-alpha fusion protein; while at relatively high concentrations (0.5–2.0 μM), it triggers apoptosis.56 Zhou et al. recently published the evidence that ATO treatment can induce rapid loss of membrane procoagulant activity and TF mRNA leading beneficial effect on the related coagulopathy in APL.57–58 However, mechanisms by which ATRA or ATO lead to the rapid resolution of coagulopathy need further definition.