The American Society of Clinical Oncology (ASCO) and College of American Pathologists (CAP) proposed original guidelines to test the HER2 status in breast cancers in 2007 and amended those guidelines in 2013 after concerns were raised about false-positive and false-negative HER2 assessments.13,14 Even though pathology communities adopted the 2007 ASCO/CAP algorithms previously, they will soon be familiar with the new 2013 modified rules all over the world. This evidence concerns the gene ERBB2 and breast cancer.