Leukemia is a heterogeneous clonal disorder of hematopoietic stem and progenitor cells, characterized by
various acquired genetic aberrations. The discovery of
abnormal fusion proteins resulting from chromosomal
rearrangements has significantly contributed to our understanding of the molecular mechanism of the pathogenesis of leukemia. The first oncogene discovered as the
direct etiological basis of a malignancy, the BCR/ABL1
translocation in chronic myeloid leukemia (CML), results
in dysregulated tyrosinase activity, which can be treated
using the tyrosine kinase inhibitor Imatinib [10,11]. The
t (15; 17) chromosomal translocation in promyelocytic
leukemia (APML, AML-M3) functions in a similar way,
generating the novel fusion protein PML/RARa, and
ATRA (all-trans retinoic acid) offers an effective therapy for APML by specifically suppressing oncogenic
activities of the PML/RARa fusion protein [12,13]. The
FISH assay is considered the gold standard for detecting these chromosomal translocations and it therefore
plays a crucial role in selecting a targeted therapy for
various leukemias