NB cells might express these proteins as the normal neural stem cells are regulated by the subfamily, MMP-2 and MMP-9, also called gelatinases.14 In fact, MMP-2 and MMP-9 have been reported to have an important role in invasion and metastasis of glioma and other cancers.15, 16 and 17. This evidence concerns the gene MMP2 and neuroblastoma.