Mutations in <i>PTPRK</i> (p.L988S), <i>PIK3CB</i> (p.F934L), <i>LRP1B</i> (p.A1912T), and <i>IGF2R</i> (p.G2052R) were predicted to significantly decrease protein stability.<h4>Conclusion</h4>This study demonstrated that PDX models effectively preserve the biological and genetic characteristics of primary gastric tumors, underscoring their utility in studying tumor heterogeneity. The gene discussed is PIK3CB; the disease is gastric neoplasm.