ESR1 and meningioma: Thus, mitotic and cell proliferation indices (Ki67), the intensity of angiogenesis, the influence of sex steroid hormones (PR, ER, AR), inflammatory markers (COX-2), tumor suppressors (p53), genetic and immunological changes and histocompatibility molecules (HLA-G and HLA-E) can contribute for toward pathogenesis and the development of meningioma.