Anti-SS1 antibodies are used in antigen-specific immunodetection in biological samples. The target SS1 is a known alias name of the protein major histocompatibility complex, class II, DR beta 1, encoded by the HLA-DRB1 gene in humans. This 266-amino acid residue protein is known to be involved in epidermis development and immune response pathways, among other biological processes. It is localized to the ER, lysosomes, and cell membrane of the cell and features ubiquitinated and glycosylated post-translational modifications. In terms of tissue expression, it is reported to be expressed in professional APCs: monocyte/macrophages, dendritic cells and B cells. Other synonyms for SS1 include DRB1, HLA-DR1B, and HLA-DRB. Some SS1 antibodies may have been used in research and have associated citations. These antibodies are most commonly used in Western Blot experiments, among other applications.