Thus, IHC analyses of patient NB samples showed that MMP2 and MMP9 were expressed together, mostly in the ECMs of tumor-adjacent stroma and endothelial cells, while TIMP2 (TIMP metallopeptidase inhibitor 2) was detected in neuroblastic tumor cells, their adjacent stromal tissue, and in endothelial cells. This evidence concerns the gene MMP9 and neuroblastoma.