This controversy has continued even after the 2007 publication by the American College of Clinical Oncology (ASCO) and the College of American Pathologists (CAP) entitled "Guideline Recommendations for Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer." Although the authors of the guideline concurred that about 20% of current HER2 testing may be inaccurate, they pointed out that HER2 status should be determined for all invasive breast cancers (Wolff et al., 2007). Here, ERBB2 is linked to breast cancer.