Anti-FSAP121 antibodies enable researchers to detect and measure the FSAP121 antigen in biological samples. This target is a reported synonym of the VIRMA gene, which encodes vir like m6A methyltransferase associated. This protein is known to function in mRNA processing and RNA splicing, among other biological roles. The human version of FSAP121 has a canonical amino acid length of 1812 residues and a protein mass of 202 kilodaltons, although 4 isoforms have been identified. It is reported to be localized in the nucleus and cytoplasm of cells and widely expressed in many tissue types. FSAP121 is a member of the Vir protein family.