Since recent data have shown that glioblastoma cancer stem cells can generate cells contributing to vessel formation (Cheng et al. 2013; Ricci-Vitiani et al. 2010), we performed double immunostaining using antibodies that selectively recognize the mutated proteins EGFRvIII and IDH1-R132H, histological hallmarks of tumor-derived glioma cells. Here, IDH1 is linked to glioblastoma.