According to the testing guidelines of the 2022 American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP), HER-2 low expression is defined as a breast cancer subgroup having immunohistochemistry (IHC) score of 1+ or 2+ and negative for fluorescence in situ hybridization (FISH−) test (5). This evidence concerns the gene ERBB2 and breast cancer.