CDO1 (Cysteine Dioxygenase Type 1): CDO1 is an enzyme that facilitates the conversion of cysteine to cysteine sulfinic acid, a key step in the metabolism of sulfur-containing amino acids. This process plays a vital role in regulating cellular cysteine levels and supporting the production of taurine and sulfate. Proper CDO1 function is important for maintaining cellular redox balance, and abnormalities in this enzyme have been associated with various health conditions, including cancer, due to cysteine’s role in cell growth and programmed cell death.