TF and acute promyelocytic leukemia: The combination therapy of ATRA and ATO is effective in inducing APL remission in newly diagnosed patients, and may provide an alternative to ATRA+chemotherapy in this disease, with less toxic effects.9 One mechanism of ATRA effect on the coagulopathy relies on its capacity to reduce the APL cell procoagulant activities (PCA) [i.e. tissue factor (TF) and cancer procoagulant (CP)].