In general, the infiltration of TAMs, CAFs, MSCs and Foxp3+ regulatory T cells and high levels of CXC chemokine receptor 4, CCRs (chemokine C-C motif receptors) 3, 4, 5 and CCR7, HIF-1α, STAT3, COX-2, orphan nuclear receptor 4A2, MMP-2, MMP-7, MMP-9, MMP-21 and macrophage-specific MMP-12 in gastric tumor were associated with poor survival of gastric cancer patients [54,105]. The gene discussed is MMP9; the disease is gastric cancer.