MMP9 and gastric cancer: Peng et al., using a semiconductor quantum dot probe, found a higher expression of LOX in GC tissues than in para-cancerous tissues, and stromal activation (high density of macrophages, high density of microvessel, low neovessel maturation, intense expression of MMP-9, and low density of type IV collagen) induced by LOX overexpression in GC leads to a poor prognosis [43].