Clinical relevance of Bmi-1 expression in human gliomas. A, Bmi-1 levels in association with MMP-9 and NF-kappaB expression in 127 primary human glioma specimens. Two representative cases, diagnosed as WHO grade I (upper row) and grade III (lower row), are shown. The insets are enlarged images derived from the original pictures. B, Percentages of all specimens (upper) and specimens in grade IV (lower) showing low- or high-Bmi-1 expression relative to the levels of MMP-9 and nuclear or cytoplasmic NF-kappaB p65 localization, analyzed by IHC staining.