The specific aims of this study were to investigate if pregnancy-related meningiomas were characterized by (1) specific histopathological features, (2) a higher expression of prolactin receptors and prolactin, (3) increased Ki-67 labeling index, and (4) the location of meningiomas in the skull-base area in close proximity to the pituitary gland. The gene discussed is PRL; the disease is meningioma.