However, it was also reported that the KD reduced ROS levels in gliomas, accompanied by slowed tumor growth and changes in ROS modulating genes, including cyclooxygenase-2 (COX-2), glutathione peroxidase 7 (Gpx7) and peroxiredoxin 4 (Prdx4) [158]. The gene discussed is PTGS2; the disease is central nervous system cancer.