NOS: not otherwise specified; T: tumor; N: nodal; HER2/neu: human epidermal growth factor receptor 2; MLH1: MutL protein homolog 1; PMS2: postmeiotic segregation increased 2; MSH2: MutS homolog 2; MSH6: MutS homolog 6; MSI: microsatellite instability. The gene discussed is ERBB2; the disease is neoplasm.