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. This evidence concerns the gene MATN3 and gastric cancer.