PTGS1 and neoplasm: Analogous effects resulted from coinfusion of COX-1–/– platelets and B16F10 cells in COX-1+/+ mice, with a decrease in platelet aggregation on tumor cells (Figure 10, A–C), association of tumor cells with activated endothelium (Figure 10, D–F), diameter of blood vessels (Supplemental Figure 11, D–F), and recruitment of monocytes/macrophages to tumor cells (Figure 10, G and H) in comparison with mice infused with COX-1+/+ platelets.