ERBB2 and breast carcinoma: According to the findings of retrospective analyses of the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-31 trial and North Central Cancer Treatment Group (NCCTG) N9831 trial, a subset of breast cancer patients resulted negative for HER2 biomarker assessment by ISH/IHC, benefited from anti-HER2 therapy (MacNeil et al., 2020).