In the phase I to phase III studies [7–10], pyrotinib was demonstrated promising antitumor activity in patients with HER2-positive metastatic breast cancer, which was approved by the National Medical Products Administration in China for treatment in combination with capecitabine in patients with relapsed or metastatic HER2-positive breast cancer previously treated with anthracycline or taxane. Here, ERBB2 is linked to breast cancer.