Anti-Matrin 3 antibodies are used in the immunodetection of the protein encoded by the MATR3 gene. In humans, the canonical protein has a reported length of 847 amino acid residues and a mass of 94.6 kDa. Its subcellular localization is in the nucleus. Alternative splicing is reported to yield 2 different isoforms for this protein. It is believed to play a role in transcription or may interact with other nuclear matrix proteins to form the internal fibrogranular network. Other names for this target antigen include MPD2, VCPDM, vocal cord and pharyngeal weakness with distal myopathy, and ALS21.