A moderate diffuse expression of GFAP and a strong diffuse expression of p53 in GBM xenografts closely resembled the distribution and staining intensities of these markers in the original patient GBM with a primitive neuronal component, whereas the Ki67 score in xenografts was lower than in the patient’s tumor (20-22% versus 40%–45%) (Supplementary Data). The gene discussed is GFAP; the disease is neoplasm.