Anti-CK antibodies enable researchers to detect and measure the CK antigen in biological samples. This target is a reported synonym of the CMPK1 gene, which encodes cytidine/uridine monophosphate kinase 1. This protein is known to function in protein phosphorylation, among other biological roles. The human version of CK has a canonical amino acid length of 196 residues and a protein mass of 22.2 kilodaltons. It is reported to be localized in the nucleus and cytoplasm of cells and widely expressed in many tissue types. CK is a member of the Adenylate kinase protein family.