In general, MMP-9-positive tumor-associated macrophages (TAMs) concomitant with the “restoration” of tumor angiogenesis and metastasis in genetically-deficient tumor bearers transplanted with wild-type hematopoietic cells [29], imply that MMP9 may be critical regulatory factor for macrophages to promote angiogenesis and sustain active of tumor invasion and metastasis. Here, MMP9 is linked to neoplasm.