DS-MB-03957 recognizes murine plasmalemma vesicle-associated protein (PLVAP), a 60kD protein which is otherwise known as MECA-32 and PV-1. PLVAP is a transmembrane homodimer which is associated with endothelial cell caveolae and fenestrae. In adult and embryonic mice, PLVAP is primarily expressed on endothelial tissues but shows restricted distribution in the skeletal, cardiac and brain tissues. In embryonic mice, PLVAP expression, on the vasculature associated with blood brain barrier has been reported to be developmentally regulated. In humans, PLVAP is selectively up-regulated in a variety of high-grade brain tumors, including glioblastoma and metastatic carcinoma, as well as other cerebral disorders associated with blood-brain barrier disruption, such as acute ischemia. PLVAP represents a novel marker of brain tumor angiogenesis and integrity of the blood-brain barrier and is a potential therapeutic target.