Two decades ago, the study of Tanaka et al. demonstrated with the use of SC-560 and celecoxib as selective COX-1 and COX-2 inhibitors, respectively, that gastric ulceration is caused when both COX-1 and COX-2 are inhibited, and the supporting evidence demonstrated that the selective COX-1 inhibition failed to generate gastric lesions [9]. The gene discussed is PTGS1; the disease is gastric ulcer.