<b>Conclusions:</b> THBS2, THBS4, and COMP were potentially diagnostic markers for GC; THBS1, THBS2, THBS4, and COMP were potentially prognostic markers for GC; investigating the relations of THBSs and tumor immunology might help in immunotherapy of GC, while more studies are needed to confirm these results. The gene discussed is COMP; the disease is gastric cancer.