 Because acute promyelocytic leukemia ( APL ) has the highest <unk> and requires a unique form of treatment , it is important to quickly establish or exclude the diagnosis of this subtype of leukemia . <unk> in situ <unk> performed on blood or bone marrow is often used for this purpose , as it readily identifies the chromosomal translocation [ t ( 15 ; 17 ) ( <unk> ; <unk> ) ; ] that <unk> APL . There is also a need to <unk> detect the presence of PML / <unk> fusion protein , which is an <unk> product of that translocation . 
