We examined ET-9 signature using K-M plotter68 and show that high ET-9 expression is associated with shorter survival in lymph node positive (HR = 1.6, CI 1.3–2.1, p = 3.8e−5), HER2 positive (HR = 2.2, CI 1.4–3.5, p = 2.3e−4), post-chemotherapy (HR = 2.7, CI 1.6–4.5, p = 2.5e−5,) and triple-negative breast cancers (HR = 3.9, CI 1.9–7.9, p = 3.1e−5). The gene discussed is ERBB2; the disease is triple-negative breast carcinoma.