ERBB2 and gastric cancer: As summarized in Fig. 5k, GC patients with MSS status might not benefit from chemotherapy and targeted therapy; GC patients with MSI status were featured by TCR activation and could benefit from the docetaxel, or trastuzumab + XELOX combined therapies; GC patients with high immune activation showed non-sensitive response to XELOX therapy; GC patients with high ECM level were resistant to anti-HER2 targeted therapy.