RBFOX3 and neoplasm: Immunohistochemically, the tumor cells were diffusely positive for GFAP (Fig. 4c), S100 (Fig. 4d), olig2 (Fig. 4e), synaptophysin, and vimentin, but negative for EMA (Fig. 4f), CD31, CD34 (Fig. 4g, h), NeuN, inhibin-α, D2-40, and IDH1 (Fig. 4i).