Fig. 1.

Immunohistochemical expression of MMP2, OPN, and ITGB1 in bone invasive and noninvasive meningiomas (original magnification ×400). a Low vascular MMP immunoexpression in a bone-invading transbasal meningioma. b High vascular MMP immunoreactivity in a noninvading skull base meningioma. The arrows indicate vascular immunostaining. c Low vascular OPN immunoexpression in a noninvading skull base meningioma. d High vascular OPN immunopositivity in a bone-invading transbasal meningioma. The arrows indicate vascular immunostaining. e Low tumoral ITGB1 immunoreactivity in a noninvading skull base meningioma. f High tumoral ITGB1 immunoexpression in a bone-invading transbasal meningioma. g Low vascular ITGB1 immunopositivity in a noninvading skull base meningioma. h High vascular ITGB1 immunoreactivity in a bone-invading transbasal meningioma in multiple layers extending from the endothelium through the media and into the adventitia. The arrows indicate vascular immunostaining