Inhibition of HER2 resulted in upregulated expression levels of STING protein and CD8+ T cell infiltration, suggesting that HER2 positivity may promote a tumor immunosuppressive microenvironment in gastric cancer by inhibiting STING expression and CD8+ T cell infiltration, thereby worsening patient prognosis [52] (Table 1). Here, ERBB2 is linked to gastric cancer.