PML and acute promyelocytic leukemia: The PML-RARα transcript subtypes referred to as long (L or bcr-1), variant (V or bcr-2), and short (S or bcr-3), depending on the location of breakpoints within the PML site (intron 6, exon 6, and intron 3), have not been clearly associated with different prognosis or ED in APL [4].