We investigated RET mRNA expression by real-time reverse-transcriptase polymerase chain reaction (RT-PCR) assay using LightCycler, and KIF5B/RET gene rearrangements using newly established fluorescence in situ hybridization (FISH) analysis in surgically treated nonsmall cell lung cancer (NSCLC) cases.    ///    "We investigated RET mRNA expression by real-time reverse-transcriptase polymerase chain reaction (RT-PCR) assay using LightCycler, and KIF5B/RET gene rearrangements using newly established fluorescence in situ hybridization (FISH) analysis in surgically treated nonsmall cell lung cancer (NSCLC) cases. "    ///    RET expression and detection of KIF5B/RET gene rearrangements in Japanese lung cancer..     ///    "Although RET IHC positivity was not perfectly correlated with KIF5B/RET arrangement, we have detected the KIF5B/RET rearrangements using FISH analysis. "    ///    "Thus, we have successfully introduced FISH for diagnosing KIF5B/RET positive lung adenocarcinoma. "    ///    "T/N ratio of RET/? actin mRNA levels was significantly higher in KIF5B/RET rearrangement samples (161.763 ?? 123.488) than in wild-type samples (5.9013 ?? 17.148, P = 0.044). "