Anti-FAM20B glycosaminoglycan xylosylkinase antibodies are used for the immunodetection of the protein encoded by the FAM20B gene. In humans, the canonical protein has a reported length of 409 amino acid residues and a mass of 46.4 kDa. Its subcellular localization is in the Golgi. It is widely expressed across many tissue types. A member of the FAM20 protein family, it is known to be important for the 2-O-phosphorylation of xylose in the glycosaminoglycan-protein linkage region of proteoglycans thereby regulating the amount of mature GAG chains. Post-translational modifications have been described, including glycosylation. Other names for this target antigen include glycosaminoglycan xylosylkinase, family with sequence similarity 20, member B, xylose kinase, and gxk1. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.