Concordance of IHC, FISH and RT-PCR for EML4-ALK rearrangements

The echinoderm microtubule-associated protein-like 4 anaplastic lymphoma kinase (EML4-ALK) is a fusion gene comprising portions of the echinoderm EML4 and ALK genes and was first found in a subset of non-small cell lung cancer (NSCLC) cells (1). EML4-ALK is formed through disruption of EML4 at a position approximately 3.6-kb downstream of exon 13 and ligation to a position 297-bp upstream of exon 21 of ALK. EML4-ALK has transforming potential that is dependent on its kinase activity, while the coiledcoil domain of EML4 mediates the constitutive dimerization and cytoplasmic activation of EML4-ALK, which together are responsible for the oncogenic activity of the fusion protein (1)