Anti-PC4 antibodies enable researchers to detect and measure the PC4 antigen in biological samples. This target is a reported synonym of the IFRD1 gene, which encodes interferon related developmental regulator 1. This protein is known to function in muscle cell differentiation, among other biological roles. The human version of PC4 has a canonical amino acid length of 451 residues and a protein mass of 50.3 kilodaltons, although 2 isoforms have been identified. It is reported to be widely expressed in many tissue types. PC4 is a member of the IFRD protein family.