MIB1 and meningioma: Although, CAV2 has not been investigated in meningioma, increased CAV1 protein immunoexpression, a family member of the caveolin family, has been reported in meningioma and associated with an increased MIB-1 index and poor prognosis [19] while CAV1 has been reported as downregulated in WHO grade I meningioma [26].