Figure 6

Expression of indoleamine 2,3-dioxygenase (IDO) in nasopharyngeal carcinoma. Normal nasopharyngeal tissue (A), tumor section from NPC type I (B), type II (C) and type III (D) were stained with antibodies to IDO, as described in Materials and Methods. Images were captured at ×100 magnification, and ×400 magnification for inserts.