We observe unambiguous HR/HER2 statuses in classes 1 and 4 (high likelihood of HR+/HER2-) yet greater heterogeneity in classes 2 and 3, a high probability of metastases in group 3, and varying probabilities of lymph node metastasis between groups (Fig 1). Here, ERBB2 is linked to metastatic malignant neoplasm in the lymph nodes.