ATRX and astrocytoma (excluding glioblastoma): In brain context, \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\upalpha$$\end{document}α-thalassemia/mental retardation syndrome X-linked protein (ATRX) is a nuclear marker in non-neoplastic cells, but lost in the tumor cells of many Isocitrate dehydrogenase 1 (IDH1)-mutated astrocytomas and glial fibrillary acidic protein (GFAP) is expressed by cells with astrocytic origin27.