In this study, we developed three assays, all of which can be used with archival formalin-fixed, paraffin-embedded tissues: (1) a sensitive reverse transcription-polymerase chain reaction (RT-PCR) assay for various X-ALK fusion genes, (2) a 5' rapid amplification of cDNA ends (RACE) assay to identify unknown fusion partners, and (3) a real-time RT-PCR assay to quantify the amount of the NPM-ALK fusion transcript.     ///    Prognostic significance of NPM-ALK fusion transcript overexpression in ALK-positive anaplastic large-cell lymphoma..     ///    Overexpression of the NPM-ALK fusion transcript may be associated with a poor prognosis of the patients with ALK(+) anaplastic large-cell lymphomas..     ///    Patients with NPM-ALK overexpression showed a significantly unfavorable overall survival compared with those with a low expression of this transcript.     ///    The real-time quantitative RT-PCR assay showed that the NPM-ALK transcript was over expressed in four of 20 quantifiable cases. 