Although all tumor cells are positive for GFAP and IDH1-R132H, the astrocytic population show strong nuclear positivity for p53 and loss of nuclear ATRX expression (Fig. 2e,g), whereas the oligodendroglial population shows minimal p53 staining with retention of ATRX nuclear expression (Fig. 2f,h). Here, ATRX is linked to neoplasm.