Because the EML4-ALK fusion was only shown by a reverse transcription-polymerase chain reaction approach, we developed fluorescent in situ hybridization assays to interrogate more than 600 NSCLCs using break-apart probes for EML4 and ALK.     ///    "We also observed that, in most cases in which an EML4/ALK alteration is detected, not all of the tumor cells harbor the lesion. "    ///    We found that EML4-ALK fusions occur in less than 3% of NSCLC samples and that EML4 and/or ALK amplifications also occur.     ///    EML4-ALK fusion lung cancer: a rare acquired event.. 