Adenosine-differentiated DCs act as angiogenic and tumor growth–promoting factor in vivo. Immature DCs were generated with or without 100 μM NECA from mouse HPCs and injected into subcutaneous LLC tumors in mice. Seven days later tumors were isolated and weighted (A), and tumor vascularization was assessed using FITC-dextran (B) or immunostaining with antibodies to CD34 (C) or von Willebrand factor (D) as described in “Mouse tumor model experiments.” Images were taken from tumor sections, and the number of tumor blood vessels identified by FITC-dextran fluorescence (green) or immunostaining (brown) was counted. Images of representative tumor sections show a higher number of blood vessels in tumors that received injection of adenosine-differentiated DCs (E). Five animals per group. Fifteen fields on 2 nonadjacent sections were counted for each sample.