Patients who underwent reduction mammoplasty were more likely to have human epidermal growth factor receptor 2+ breast cancer (12.4% vs 7.7%; P = 0.044) and less likely to have metastatic disease at the time of diagnosis (0% vs 5.1%; P = 0.043) compared to patients with breast cancer who did not have reduction mammoplasty (Supplemental Table 1, http://links.lww.com/AOSO/A242). The gene discussed is ERBB2; the disease is metastatic neoplasm.