ERBB2 and breast cancer: Roca et al., in a prospective clinical trial performed in 132 patients with HER2+ BC and treated sequentially with adjuvant chemotherapy and trastuzumab (UNICANCER-PACS04), observed that the presence of the H allele was associated with a better EFS than in R/R genotype patients at 5 years of follow-up (90.3% vs 69.7%; p=0.027) (22).