Tissue specific overexpression of putative oncogenes of interest, using methods which link the gene of interest to a glial specific promoter such as GFAP, S100β, or Nestin, provides an appealing approach towards the creation of spontaneously occurring brain tumors in animals that lack the pan-immune dysfunctions seen in many germline knockout animals [75]. The gene discussed is GFAP; the disease is brain neoplasm.