MMP9 and B-cell chronic lymphocytic leukemia: For example, CCL21/CCR7 promotes G2/M phase progression and prevents apoptosis via the ERK pathway in human non-small cell lung cancer[15, 16], facilitates the progression of pancreatic cancer via induction of angiogenesis and lymphangiogenesis[14], regulates matrix metalloproteinase-9 (MMP-9) in human colon cancer metastasis[18], and upregulates MMP-9 in B-cell chronic lymphocytic leukemia cell migration and invasion [17].