Anti-CLSPa antibodies enable researchers to detect and measure the CLSPa antigen in biological samples. This target is a reported synonym of the C1RL gene, which encodes complement C1r subcomponent like. This protein is known to function in innate immune responses, among other biological roles. The human version of CLSPa has a canonical amino acid length of 487 residues and a protein mass of 53.5 kilodaltons. It is reported to be a secreted protein that is notably expressed in many tissues, such as the bronchus, testis, and appendix. Other names for this target antigen include C1RL1, C1RLP, and C1r-LP.