Recently, with the rapid development of immune checkpoint blockade therapies for solid tumours, the combination of pembrolizumab, trastuzumab and chemotherapy has been shown to result in promising clinical outcomes as a first-line treatment for patients with unresectable or metastatic HER2-positive GC, with significantly increased objective response rates (ORRs) and prolonged progression-free survival (PFS), as demonstrated by the phase III KEYNOTE-811 trial (7). This evidence concerns the gene ERBB2 and gastric cancer.