Anti-OS9 endoplasmic reticulum lectin antibodies are used for the immunodetection of the protein encoded by the OS9 gene. In humans, the canonical protein has a reported length of 667 amino acid residues and a mass of 75.6 kDa. Its subcellular localization is in the ER. Alternative splicing is reported to yield 8 different isoforms for this protein. It is ubiquitously expressed across many tissue types. A member of the OS-9 protein family, it is known to be involved with protein ubiquitination. Post-translational modifications have been described, including N-glycosylation. Other names for this target antigen include protein OS-9, amplified in osteosarcoma 9, endoplasmic reticulum lectin 2, erlectin 2, and ERLEC2. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish and chimpanzee species.