Figure 1: Representative iNOS staining of (a) group 1 (low in cancer cells and macrophages: iNOS grades 0 to 1 cancer cells and iNOS grades 0 to 1 macrophages) (×100), (b) group 2 (low in cancer cells and high in macrophages: iNOS grades 0 to 1 cancer cells and iNOS grades 2 to 3 macrophages) (×100), (c) group 3 (high in cancer cells and low in macrophages: iNOS grade 2 cancer cells and iNOS grades 0 to 1 macrophages) (×40), and (d) group 4 (high in cancer cells and macrophages: iNOS grade 2 cancer cells and iNOS grades 2 to 3 macrophages) (×40) tumors. The intensity of iNOS staining was usually higher in infiltrating macrophages (arrowheads) than in cancer cells (arrows).