ZD:Cox-2−/− mice had significantly greater tongue/esophageal tumor incidence than ZD:WT littermates, and ZD:Cox-2−/− and ZD:Cox-2+/− mice showed significantly higher tumor multiplicity in all three sites (tongue, esophagus and forestomach) than ZD:WT controls (incidence, Fig. 1a; multiplicity, Fig. 1b, Supporting Information Table 1). This evidence concerns the gene PTGS2 and neoplasm of esophagus.