Immunolocalization of Survivin ΔEx3 in brain tumors and angiomas. Formalin-fixed paraffin-embedded tissues were immunostained with antibodies against Survivin, Survivin ΔEx3, CD31, or CD34. Survivin ΔEx3 localized to the vascular endothelium of the brain tumor (A-B) and angioma tissues (C-E arrowhead). Vascular endothelial cells staining positive for Survivin ΔEx3 were also positive for CD31 (D) and CD34 (E). Survivin ΔEx3 was not visualized within the lymphatic endothelium (D, arrow). Survivin was not detected in angioma tissues (E). The tissues represented include (A) medulloblastoma, (B) ependymoma, (C) capillary venous angioma, (D) lymphangioma, and (E) pyogenic granuloma.