Compared with lapatinib plus capecitabine, pyrotinib plus capecitabine exhibited an over 20% increase in objective response rate (ORR), a significant benefit in progression-free survival (median, 12.5 versus 6.8 months; hazard ratio [HR], 0.39), and a clear trend towards improvement in overall survival (median, not reached versus 26.9 months; HR, 0.69) in patients with pretreated metastatic HER2-positive breast cancer [12–14]. This evidence concerns the gene ERBB2 and breast cancer.