Of a total of 88 breast tumors (DIN1C-3, invasive carcinomas) consecutively diagnosed in the first half of 2007, 73 tumors (83%) revealed no expression of HER2 (score 0) by our routine immunohistochemical assay, evaluated according to the pre-ASCO/CAP guidelines. The gene discussed is ERBB2; the disease is invasive carcinoma.