Anti-P/cl.18 antibodies enable researchers to detect and measure the P/cl.18 antigen in biological samples. This target is a reported synonym of the CPSF1 gene, which encodes cleavage and polyadenylation specific factor 1. This protein is a known component of the cleavage and polyadenylation specificity factor (CPSF) complex that plays a key role in pre-mRNA 3'-end formation, recognizing the AAUAAA signal sequence and interacting with poly(A) polymerase and other factors to bring about cleavage and poly(A) addition. The human version of P/cl.18 has a canonical amino acid length of 1443 residues and a protein mass of 160.9 kilodaltons. It is reported to be localized in the nucleus of cells. Other names for this target antigen include CPSF160, HSU37012, and MYP27.