For instance, a minor proportion of APL, also classified as AML with an APL-like morphology, does not have the typical PML-RARA fusion gene but chromosomal translocations involving different RARA gene partners (X-RARA chimeric transcripts such as PLZF-RARA [10], or NPM1-RARA fusion oncoproteins [11]) that are associated with a worse prognosis due to the lack of the ATO-binding region in the PML protein [1,11]. This evidence concerns the gene RARA and acute myeloid leukemia.