Anti-transmembrane O-mannosyltransferase targeting cadherins 4 antibodies are used for the immunodetection of the protein encoded by the TMTC4 gene. In humans, the canonical protein has a reported length of 741 amino acid residues and a mass of 83 kDa. Its subcellular localization is in the ER and membrane. Alternative splicing is reported to yield 4 different isoforms for this protein. It is a member of the TMTC protein family. Other names for this target antigen include transmembrane and TPR repeat-containing protein 4, transmembrane and tetratricopeptide repeat containing 4, and protein O-mannosyl-transferase TMTC4. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.