Anti-US9 antibodies enable researchers to detect and measure the US9 antigen in biological samples. This target is a reported synonym of the RPS16 gene, which encodes ribosomal protein S16. This protein is known to function in protein translation and rRNA processing, among other biological roles. The human version of US9 has a canonical amino acid length of 146 residues and a protein mass of 16.4 kilodaltons. It is reported to be localized in the nucleus and cytoplasm of cells and widely expressed in many tissue types. US9 is a member of the Universal ribosomal protein uS9 protein family.