PGR and meningioma: The MIB-1 labeling index in sporadic cranial meningiomas is influenced by several factors, such as the anatomical location of the meningioma, sex, the density of CD68+ macrophage infiltrates, cyclooxygenase-2 (COX-2) expression, autocrine inhibitory inflammatory regulation, and progesterone receptor status [47,49,50,51,52].