ERBB2 and rectal cancer: Herein, we report a rare case of rectal cancer harboring HER2 amplification with multiple metastases in the brain, scalp, lung, pancreatic head, and both kidneys, who has been treated with standard chemotherapy and several HER2 inhibitors, finally achieved notable response (nearly complete response) from pyrotinib and tegafur combined with radiotherapy (Figure 1).