For further evaluation of the meningiomas, immunohistochemistry for vimentin (Vimentin, monoclonal mouse, diluted 1:100, Dako, Santa Clara, USA), pan-cytokeratin (AE1/AE3, monoclonal mouse, diluted 1:500, Dako), glial fibrillary acidic protein (GFAP, polyclonal rabbit, diluted 1:1000, Dako) or S-100 protein (S-100, polyclonal rabbit, diluted 1:800, Sigma-Aldrich, St. The gene discussed is GFAP; the disease is meningioma.