PTGS2 and neoplasm: Alternatively, Sawaoka et al (1998) and Tsujii et al (Tsujii and DuBois, 1995; Sawaoka et al, 1998; Tsujii et al, 1998) have suggested that a decrease in angiogenesis may account for the inhibitory properties of COX-2 selective NSAIDs on tumour growth.