ERBB2 and breast cancer: In addition, this heterogeneous expression pattern of MnSOD was also confirmed by immunostaining in all four types of breast cancer cell lines tested in this study, including ER+/HER2-, MCF7 and T-47D; ER+/HER2+, BT474; ER-/HER2+, SK-BR-3; and triple negative, MDA-MB-468 and MDA-MB-231 [25] (Figure 6B).