Across treatment regimens, <i>FGFR2</i> and <i>MET</i> alterations were linked to poorer outcomes, whereas <i>PIK3CA</i> mutations were observed in patients with longer overall survival after first-line chemotherapy.<h4>Conclusion</h4>Our findings provide a comprehensive genomic landscape of Korean gastric cancer and underscore the clinical relevance of integrating genomic and established biomarkers to advance precision oncology. The gene discussed is PIK3CA; the disease is gastric cancer.