Through LASSO analysis, we identified 13 macrophage-associated genes that are significantly correlated with GC clinical outcomes, including CPNE8, AKR1B1, MARCKS, ANXA5, SERPINE1, GAMT, SNCG, MATN3, SLC7A2, CYTL1, LIN7A, GJA1, APOD. The gene discussed is GAMT; the disease is gastric cancer.