AREG increased the number of α-SMA-positive vessels in LLC tumors. (A) CD31 and α-SMA staining of LLC tumors. LLC tumor sections were obtained from C57BL/6 mice coinjected with LLC cells and supernatants of BMDCs treated with LPS or LPS+ATPγS. Tumor sections were stained with Hoechst (blue) and with anti-CD31 (green) or anti–α-SMA (red). Arrows indicate CD31/α-SMA–double positive vessels (20×/0.4 numeric aperture [NA] objective). (B) Quantification of α-SMA and CD31–double positive vessels. Supernatants of BMDCs treated with LPS or LPS+ATPγS were incubated in the presence or the absence of an anti–mouse AREG blocking antibody. C57BL/6 mice were then coinjected with LLC cells and 100 μL of BMDC supernatants. At least 7 tumors (10 fields/tumor) were analyzed for each condition. The Student t test was performed using Prism 5.0 software (**P < .01). (C) SMA-positive cells express EGFR. Immunofluorescence analysis demonstrated colocalization of α-SMA expression (red) and EGFR (green) within tumor sections. Nuclei are stained with Hoechst (blue). Arrows indicate α-SMA and EGFR–double positive cells (20×/0.4 NA objective).