MMP2 and neoplasm: We have described a proangiogenic function in NK cells isolated from the peripheral blood and tumor-infiltrated cells of cancer patients (54, 58–60) and the expression of angiogenin, CXCR4/CXCL12, MMP2, MMP9, and tissue inhibitor for MMP (TIMP)-1 and TIMP-2 in NK cells from the peripheral blood and tumor-infiltrated cells of patients with colon cancer (59), which are molecules also secreted by dNK cells (55, 65–67).