To further verify the effect of COX-2 siRNA silencing COX-2 gene on cell growth of Capan-2 human pancreatic cancer cells, Capan-2 cells transfected with COX-2 siRNA were subcutaneously inoculated into BALB/c-nu/nu nude mice to investigate the effect of COX-2 siRNA on tumorigenicity of Capan-2 cells. The gene discussed is PTGS2; the disease is pancreatic neoplasm.