Probably responsible for the uptake of cobalt ions. It appears to act in a dosage-dependent manner to counteract the adverse effects of cobalt ions on cells. It may participate in the regulation of cobalt levels under normal physiological conditions and may be important in the supply of metal that is required for metalloenzyme or cofactor synthesis. It reduces the toxicity of cobalt and rhodium ions. Other components responsible for cobalt transport exist. Another possibility exists that it is associated with another unidentified membrane that has been enriched in the mitochondrial membrane fractions. Present with 2070 molecules/cell in log phase SD medium. Belongs to the cation diffusion facilitator (CDF) transporter (TC 2.A.4) family. SLC30A subfamily.