GFAP and neoplasm: Further immunohistochemical analysis revealed that the tumor cells were positive for tri-methylation of histone H3 at lysine 27 (H3K27me3), partially positive for caldesmon, and negative for glial fibrillary acidic protein (GFAP), oligodendrocyte lineage transcription factor 2 (Olig-2), myogenin, myogenic differentiation 1 (MyoD1), and SRY-related HMG-box 10 (SOX10).