GSR and cancer: Other experimentally relevant markers have been assessed in supplementation studies that suggest efficacy of n-3 fatty acids in modulating cancer outcomes including decreased vascular endothelial growth factor (VEGF) [47] and oxidative status [50], increased glutathione reductase, antioxidant status [16], superoxide dismutase [16,20] and phagocytosis and H2O2 [20] in plasma or peripheral blood mononuclear cells and decreased VEGF [8], carcinoembryonic antigen [34] and gene expression of matrix metalloproteinase (MMP)-1 and MMP-9 [30] in tumors.