A brain tumor is any intracranial tumor created by abnormal and uncontrolled cell division, normally either found in the brain itself (neurons, glial cells (astrocytes, oligodendrocytes, ependymal cells), lymphatic tissue, blood vessles), in the cranial nerves (myelin-producing Schwann cells), in the brain envelopes (meninges), skull, pituitary and pineal gland, or spread from cancers primarily located in other organs (metastatic tumors). Primary (true) brain tumors are commonly located in the posterior cranial fossa in children and in the anterior two-thirds of the cerebral hemispheres in adults, although they can affect any part of the brain. In the United States in the year 2000, it was estimated that there were 16,500 new cases of brain tumors which accounted for 1.4 percent of all cancers, 2.4 percent of all cancer deaths, and 20–25 percent of pediatric cancers. Ultimately, it is estimated that there are 13,000 deaths/year as a result of brain tumors.

Endosialin (tumor endothelial marker 1, TEM1)

• abundantly expressed in highly malignant and invasive brain tumors. PMID: 15624764

PGD-S (Prostaglandin D synthetase)

• a 30 kDa glycoprotein also known as beta-trace protein that catalyzes the formation of prostaglandin D2 (PGD2) from PGH2, is a potentially useful marker for brain tumor. PMID: 9844724

PV-1 (Plasmalemmal vesicle associated protein-1)

• represents a novel marker of brain tumor angiogenesis and integrity of the blood-brain barrier and is a potential therapeutic target. PMID: 16278383