The cells in both benign and malignant parts were positive for vimentin and epithelial membrane antigen (EMA), partially positive for S-100, but negative for cytokeratin, Schwann/2E, glial fibrillary acidic protein (GFAP) and Olig2, suggesting that the tumor cells originated from a meningioma (Fig. 2c-i, l-r). The gene discussed is GFAP; the disease is meningioma.