The results revealed that fibroblasts with knockdown of MMP1 significantly decreased the incidence of micro-metastases foci (cellular dissociation in small cellular groups, n < 15) and lymph node metastasis in the tongue transplant (Fig. 7A, B), suggesting that MMP1 originating from fibroblasts is implicated in the invasive and metastatic phenotype of tumors. The gene discussed is MMP1; the disease is metastatic malignant neoplasm in the lymph nodes.