MMP9 and central nervous system cancer: Among glial neoplasms, MMP-9 immunohistochemical expression (Table 1) was absent in vessels and diffusely present in glioma cells, both cytoplasmic and nuclear, when of grade II; in grade III gliomas the signal was weaker only cytoplasmic in glioma cells and almost lacking in neoplastic vessels, were observable; in glioblastomas (grade IV), instead, a strong reactivity was detected in neoplastic vesels in comparison with gliomatous cells that were almost completely silent.