Anti-mediator complex subunit 12L antibodies are used for the immunodetection of the protein encoded by the MED12L gene. In humans, the canonical protein has a reported length of 2145 amino acid residues and a mass of 240.1 kDa. Its subcellular localization is in the nucleus. Alternative splicing is reported to yield 4 different isoforms for this protein. A member of the Mediator complex subunit 12 protein family, it is believed to be a component of the Mediator complex, a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. The gene encoding this protein is implicated in Nizon-Isidor syndrome. Other names for this target antigen include mediator complex subunit 12 like, mediator of RNA polymerase II transcription, subunit 12 homolog-like, no opposite paired repeat protein, and mediator of RNA polymerase II transcription subunit 12-like protein. Gene orthologs have been identified in the mouse, rat, bovine, chimpanzee and chicken species.