Immunohistochemical staining of MMP1 revealed a reduced positive signal in tumor xenografts and pulmonary metastatic lesions generated from AEG-1-knockdown HNSCC cells, as compared to the cytosolic and juxtacellular staining of MMP1 observed in lesions arising from control cells (Figure 4D). The gene discussed is MTDH; the disease is head and neck squamous cell carcinoma.