Anti-CI-9k antibodies enable researchers to detect and measure the CI-9k antigen in biological samples. This target is a reported synonym of the NDUFA4 gene, which encodes NDUFA4 mitochondrial complex associated. This protein is known to function in electron transport, among other biological roles. The human version of CI-9k has a canonical amino acid length of 81 residues and a protein mass of 9.4 kilodaltons. It is reported to be localized in the mitochondria of cells and widely expressed in many tissue types. Other names for this target antigen include CI-MLRQ and COXFA4.