ERBB2 and breast cancer: To this end, we applied the HER2 RollFISH probe validated above (consisting of 48 ODNs) to detect HER2 transcripts in 75 samples represented in duplicate on a single tissue microarray (TMA), including normal breast tissue as well as breast cancers with HER2 IHC score ranging from 0 to 3 + (Supplementary Fig. 9a, b, Supplementary Tables 4 and 5, and Methods).