ERBB2 and breast cancer: We found ERBB2 amplification in 26.5% of breast cancers and 13% of familial breast cancers (Supplementary Figure S2A, available at https://doi.org/10.1016/j.esmoop.2022.100540); the higher prevalence detected in breast cancer may be due to the threshold we used to define an amplification (of >6 copies with no correction for ploidy), while the lower presence in the familial breast cancers is due to the presence of familial BRCA-associated tumours which tend to be HER2 negative.