Expression of CD160 in tumor blood vessels but not in the blood vessels of healthy tissues. (A) Representative sections of B16 melanoma at day 16 after their subcutaneous injection (top) and healthy mouse heart (bottom), both stained with either CL1-R2 (CD160) or isolectin B4, an endothelial cell marker. Bar, 50 µm. Images are representative of four independent experiments (five mice/group). (B) Sections of human colon tumor (top) and healthy colon (bottom) stained with CL1-R2 (CD160) or a mAb against CD31, a human endothelial cell marker. Images are representative of two patient biopsies. Control IgG1 did not stain and is not shown. Bar, 50 µm.