Among primary breast cancer patients, the highest neutrophil cytotoxicity was in the ER+/HER2− breast cancer patients, which is traditionally the most favorable subtype of breast cancer9 and that the average neutrophil cytotoxicity of ER−/ HER2+ patients was the lowest of all our samples, including controls, although sample sizes were too small to assess the significance of this result. This evidence concerns the gene ERBB2 and breast cancer.