Model illustrating CdCl2 displacing Zn in TET proteins and histone demethylases. Similarities in physical and chemical properties between Cd and Zn enable them to antagonize each other. Cd has the potential to displace Zn in the Zn finger DNA binding domain of TET protein, which can lead to changes in conformation and activity. Abbreviations: 5-hmC, 5-hydroxymethylcytosine; Cd, cadmium; Cl, chlorine; COOH, carboxylic acid; Cys, cysteine; His, histidine; TET, ten-eleven translocation; Zn, zinc.