CDO1 and central nervous system cancer: A central biochemical axis that links redox control in gliomas is the transsulfuration pathway and L-cysteine-metabolizing enzymes, such as cysteine dioxygenase 1 (CDO1), cystathionine β-synthase (CBS; EC 4.2.1.22), cystathionine γ-lyase (CTH; EC 4.4.1.1), 3-mercaptopyruvate sulfurtransferase (MPST; EC 2.8.1.2), and thiosulfate sulfurtransferase (TST; rhodanese; EC 2.8.1.1) (Figure 1) [15,16,17,18,19,20].