In a systematic review including 7 studies about the role of HER2/neu as a prognostic factor for survival and relapse in pT1a-bN0M0 breast cancers, HER2 positivity in small breast tumors appeared to be associated with a worse outcome regarding breast cancer-specific survival, relapse-free survival, and distant relapse-free survival [13]. This evidence concerns the gene ERBB2 and breast cancer.