Anti-collagen type XXI alpha 1 antibodies are used in antigen-specific immunodetection in biological samples. The target collagen type XXI alpha 1 is a known alias name of the protein collagen type XXI alpha 1 chain, encoded by the COL21A1 gene in humans. This 957-amino acid residue protein is a member of the Fibril-associated collagens with interrupted helices (FACIT) protein family. It is localized to the extracellular matrix, cytoplasm, and is secreted of the cell and features glycosylated post-translational modifications.