Type A cultures form tumor spheres, grow as intracranial xenografts and express astroglial and stem cell-related genes including GFAP (Glial Fibrillary Acidic Protein), SOX2 (SRY (sex determining region Y)-box 2) and PDGFRA (Platelet Derived Growth Factor Receptor α). The gene discussed is GFAP; the disease is neoplasm.