We conclude that the frequency of the ESRRA/C11orf20 gene fusion in serous ovarian carcinomas of stages III and IV must be considerable less than that reported previously (0/163 in our experience compared with 10/67 in the previous study).     ///    Low frequency of ESRRA-C11orf20 fusion gene in ovarian carcinomas..     ///    "in 2011, who used deep paired-end sequencing to detect the fusion gene ESRRA-C11orf20 in 10 out of 67 (15%) serous ovarian carcinomas examined, a finding that holds great promise for our understanding of ovarian tumorigenesis as well as, potentially, for new treatment strategies. "    ///    "We wanted to test how frequent the ESRRA/C11orf20 fusion is in ovarian carcinomas of all subtypes, and therefore examined a series of 230 ovarian carcinomas of which 197 were of the serous subtype and 163 of the 197 were of stages III and IV--that is, the very same carcinoma subset where the fusion transcript had been found. "    ///    "We used the same primers described previously for the detection of the fusion and the same primer combination, but found no ESRRA/C11orf20 fusion in our series. "    ///    A synthetic DNA plasmid containing the reported ESRRA/C11orf20 fusion was included as a positive control for our PCR experiments. 