PML and acute promyelocytic leukemia: The identification of molecular markers in AML has facilitated the discrimination of biologically and clinically distinct subgroups; furthermore, the correlation of mutational landscape with these and other “omic” data sets may further refine our understanding of AML biology, improve outcome prediction and treatment choices, such as the case of APL that the identification and study of the PML-RARA marker allowed the development of a specific treatment with ATRA.