ERBB2 and neoplasm: Likewise, a meta-analysis showed that the co-expression of HER2 and HR was associated with age < 40 y/o (12% vs. 6%), tumor > 2.0 cm (53% vs. 39%), positive ALN (56% vs. 42%), and tumor grade III (56% vs. 29%) compared to HR+ /HER2– patients [19].