Receptors for the steroidal hormones estrogen (ERα) and progesterone (PR) have been reported to be expressed in most meningiomas: ERα presence has been associated with increased proliferation and the development of high-grade tumors, while the high expression of PRs has been correlated with Grade 1 tumors according to the WHO grading system [81]. This evidence concerns the gene WNK3 and meningioma.