A subset of lung cancers harbors a small inversion within chromosome 2p, giving rise to a transforming fusion gene, EML4-ALK (echinoderm microtubule-associated protein-like 4 gene and the anaplastic lymphoma kinase gene), which encodes an activated tyrosine kinase.    ///    " A subset of lung cancers harbors a small inversion within chromosome 2p, giving rise to a transforming fusion gene, EML4-ALK (echinoderm microtubule-associated protein-like 4 gene and the anaplastic lymphoma kinase gene), which encodes an activated tyrosine kinase. "    ///    "We have earlier examined the presence of EML4-ALK by multiplex reverse transcription-polymerase chain reaction in 363 specimens of lung cancer, identifying 11 adenocarcinoma cases featuring the fusion gene. "    ///    "EML4-ALK lung cancers are characterized by rare other mutations, a TTF-1 cell lineage, an acinar histology, and young onset."    ///    "EML4-ALK lung cancers are characterized by rare other mutations, a TTF-1 cell lineage, an acinar histology, and young onset.. "    ///    "Furthermore, the presence of EML4-ALK appears to be mutually exclusive for EGFR and KRAS mutations (P=0.00018), whereas coexisting with TP53 mutations at a low frequency (1/11=9.1%), and correlating with non- or light smoking (P=0.040), in line with the TTF-1 immunoreactivity. "