 The incidence and clinical significance of the TMPRSS2:ERG gene fusion in prostate cancer has been investigated with contradictory results.     ///    Total RNA from 194 formalin-fixed and paraffin-embedded prostate cancer samples obtained by radical prostatectomy was subjected to reverse-transcriptase polymerase chain reaction to detect the common TMPRSS2:ERG T1-E4 and T1-E5 fusion transcripts and five other non-TMPRSS2:ERG fusion transcripts.     ///    "To exclude the possibility that Japanese prostate cancer displays novel TMPRSS2:ERG transcript variants or has unique 5' fusion partners for the ETS genes, we performed 5' RACE using fresh-frozen prostate cancer samples. "    ///    Internodular heterogeneity of TMPRSS2:ERG was observed in 5 out of 11 multifocal cases (45%).     ///    "The frequencies of both TMPRSS2:ERG- and non-TMPRSS2:ERG-positive cases were lower than those reported for European, North American or Brazilian patients. "    ///    "We identified 54 TMPRSS2:ERG-positive cases (54/194, 28%) and two HNRPA2B1:ETV1-positive cases (2/194, 1%). "    ///    "Because we identified a relatively low frequency of TMPRSS2:ERG and other fusions, further evaluation is required before this promising molecular marker should be introduced into the management of Japanese prostate cancer patients.. "