The results of the KEYNOTE-811 trial, which demonstrated the clinical benefit of combining trastuzumab with pembrolizumab (a PD-1 inhibitor) in HER2-positive, PD-L1-positive GC, may represent a significant shift in the treatment paradigm, especially when combined with immunotherapy in selected patient subgroups [96]. The gene discussed is PDCD1; the disease is gastric cancer.