A basic research, through an in vitro study, using breast cancer cell lines of four different subtypes (Luminal-A, luminal-B, HER2 type and TNBC) in normoglycemic settings, failed to show added neoadjuvant value for metformin when compared to a taxane agent alone (Sadighi et al., 2014). Here, ERBB2 is linked to breast carcinoma.