Given the small number of samples in the subgroup analysis of the clinical subtypes, we have compared the prevalence of 19q12 amplification in ER-negative/HER2-negative vs the other subtypes using the Fisher's exact test, which confirmed a significance association between 19q12 amplification and ER-negative/HER2-negative breast cancers (P = 0.0024). This evidence concerns the gene ERBB2 and breast cancer.