Fig. 2.

N32 gliomas express COX-2 in vivo and only a small portion of the COX-2 expression originates from the tumor-infiltrating macrophages and the microglial cells. Expression of c COX-2 and ED-2 as well as d COX-2 and mononuclear phagocytes (MNP) was determined using immunohistochemistry and arrows indicate double-positive cells. b, e As negative control, the primary antibodies were omitted. Images were taken at a–b ×10 and c–e ×40 magnification, and staining was performed twice