ERBB2 and breast cancer: In the literature, there are other examples that compare FISH and RT-PCR in different settings [27, 31, 32]: in breast cancer the comparison between both techniques in the determination the HER2 status has shown a good concordance ranging between 80–97% [33–35]; in the case of dermatofibrosarcoma protuberans, this concordance is of 67% for detection of COL1A1-PDGFB rearrangement [28]; and finally, in Ewing Sarcomas, several studies showed concordances between 55.5 and 100% [31, 36–38].