 The genome of a subset of non-small-cell lung cancers (NSCLC) harbors a small inversion within chromosome 2 that gives rise to a transforming fusion gene, EML4-ALK, which encodes an activated protein tyrosine kinase.     ///    "Although breakpoints within EML4 have been identified in introns 13 and 20, giving rise to variants 1 and 2, respectively, of EML4-ALK, it has remained unclear whether other isoforms of the fusion gene are present in NSCLC cells. "    ///    "Although breakpoints within EML4 have been identified in introns 13 and 20, giving rise to variants 1 and 2, respectively, of EML4-ALK, it has remained unclear whether other isoforms of the fusion gene are present in NSCLC cells."    ///    A lung cancer cell line expressing endogenous variant 3 of EML4-ALK underwent cell death on exposure to a specific inhibitor of ALK catalytic activity.     ///    Identification of novel isoforms of the EML4-ALK transforming gene in non-small cell lung cancer..     ///    Both variants 3a and 3b of EML4-ALK exhibited marked transforming activity in vitro as well as oncogenic activity in vivo. 