Anti-FAM209B antibodies are used in the immunodetection of the protein family with sequence similarity 209 member B. In humans, the canonical protein has a reported length of 171 amino acid residues and a mass of 19.5 kDa. Its subcellular localization is in the nucleus. It is notably expressed in the testis. A member of the FAM209 protein family, FAM209B is believed to play a role in sperm acrosome biogenesis. Synonyms for this target antigen include protein FAM209B and uncharacterized protein C20orf107. FAM209B gene orthologs have been reported in the mouse and chimpanzee species. Immunofluorescence is the most common application for the FAM209B antibodies listed below. Immunocytochemistry and Immunohistochemistry are also common applications.