Anti-Myosin XIX antibodies are used in the immunodetection of the protein encoded by the MYO19 gene. In humans, the canonical protein has a reported length of 970 amino acid residues and a mass of 109.1 kDa. Its subcellular localization is in the membrane, mitochondria, and cytoplasm. Alternative splicing is reported to yield 4 different isoforms for this protein. It is found to be widely expressed in multiple tissues and cell lines. The myosin XIX protein is a member of the Myosin protein family. Other names for this target antigen include myosin head domain containing 1, myosin head domain-containing protein 1, and unconventional myosin-XIX.