PTGS2 and neoplasm: At the same time it must also be expected that depletion of GSH or other antioxidant nutrients in the malnourished patient will lead to enhancement of COX-2 expression and the rate of prostacyclin synthetase inactivation in tumour endothelial cells, which means enhancement of the rate of PGH2 release from the latter [203] and more PGH2-induced and PGE2-induced (when the tumor cells express PGE synthase [203]) stimulation of tumour angiogenesis.