HPGDS and cancer: It is well known that ROS level and the activity of antioxidant enzymes (glutathione peroxidase—GPX, glutathione-S-transferase, catalase, superoxide-dismutase—SOD, hem-oxygenase 1, NAD(P)H quinone oxidoreductase 1, glutamate/cysteine antiporter solute carrier family 7 member 11—xCT, etc.)in MDR cancer cells are overexpressed compared to non-MDR cells [185,186].