ERBB2 and cancer: The overall mutation rate in both coding and non-coding regions was significantly higher in ER-negative/HER2-negative compared with HER2-positive and ER-positive/HER2-negative cancers (P = 2.8E–03 and P = 2.4E–07, respectively), which is consistent with the extensive genomic instability characterizing triple-negative breast tumours (TNBC) (Fig. 1b, c).