A significant correlation to tumor volume and/or necrosis (Gállego Pérez‐Larraya et al., 2014; Jung et al., 2007; Kiviniemi et al., 2015) and the number of GFAP positive necrotic cells (Jung et al., 2007) has been described, although in other studies a correlation to tumor volume was assessed but absent (Baumgarten et al., 2018; Ilhan‐Mutlu et al., 2013; Vietheer et al., 2017). Here, GFAP is linked to neoplasm.