Anti-C13 antibodies are used in antigen-specific immunodetection in biological samples. The target C13 is a known alias name of the protein SPT20 homolog, SAGA complex component, encoded by the SUPT20H gene in humans. This 779-amino acid residue protein is known to be required for MAP kinase p38 (MAPK11, MAPK12, MAPK13 and/or MAPK14) activation during gastrulation. It is localized to the nucleus of the cell. In terms of tissue expression, it is reported to be highly expressed in the testis, moderately in the brain and pituitary gland.