PTGS2 and neoplasm: We found that xenograft tumours from mice treated with SP had significantly elevated expression of PTGS1 (Figure 4A) and PTGS2 (Figure 4B) mRNA compared to controls (3.1±0.1 fold; P<0.01 and 6.2±0.2 fold; P<0.001 for SP vs control for PTGS1 and PTGS2 respectively).