RARA and acute promyelocytic leukemia: It was noted that the WHO (2017) (9) AML-NOS subcategory closely matched the FAB (1976) AML with maturation (FAB M2) subcategory (8,14,15).The presence of APL with PML-RARA, with concomitant disseminated intravascular coagulation (DIC) and CNS involvement, typically led to a very poor prognosis (9,19,23).