Among these miR-34a targets the increased levels of Matrix metalloproteinase 9 (Mmp9) might play an important role in the enhanced progression of Mir34aΔMye CACs, because it has been shown that neutrophil-secreted Mmp9 can break down collagen and remodel the ECM to promote tumor cell invasion and metastasis [49]. This evidence concerns the gene MMP9 and neoplasm.