Anti-myosin IXB antibodies are used in the immunodetection of the protein encoded by the MYO9B gene. In humans, the canonical protein has a reported length of 2157 amino acid residues and a mass of 243.4 kDa. Its subcellular localization is in the cytoplasm. Alternative splicing is reported to yield 2 different isoforms for this protein. It is notably expressed in peripheral blood leukocytes. A member of the Myosin protein family, it is known to be involved with GPCR signaling pathways. Other names for this target antigen include MYR5, unconventional myosin-IXb, unconventional myosin-9b, and CELIAC4.