Representative fluorescent photomicrographs showing the presence of CD8+ cytotoxic T-lymphocytes and CD56+ natural-killer T cells in the four ureteral disease types: (a) ureteral polyps; (b) ureteral papilloma; (c) high-grade ureteral cancer; and (d) low-grade ureteral cancer. CD8 is stained red and CD56 is stained green. The nuclei are stained blue with DAPI. Arrows show the double-positive stained cells. Scale bar 50 µm. The colour version of this figure is available at: http://imr.sagepub.com. DAPI, 2-(4-amidinophenyl)-6-indolecarbamidine dihydrochloride.