SOX2 and neoplasm: Immunohistochemical analysis revealed that the tumor cells exhibited diffuse positivity for GFAP (mouse monoclonal, clone GA5, prediluted; Leica Biosystems, IL, USA) and S‐100 protein (rabbit polyclonal; DAKO Agilent, CA, USA; 1:3000), mild positivity for SOX2 (rabbit polyclonal; SEven Hills Bioreagents, OH, USA; 1:2000), and focal positivity for synaptophysin (mouse monoclonal, clone 27G12; Leica Biosystems, IL, USA; prediluted) (Fig. 2).