Anti-Fritz antibodies are protein reagents that detect specific antigens. The Fritz antigen is another term for the human protein frizzled related protein, encoded by the FRZB gene. The protein is known to function in the Wnt signaling pathway and hepatocyte differentiation, among other biological roles. Canonically, it has an amino acid length of 325 residues and a mass of 36.3 kilodaltons. It is a secreted protein and it is notably expressed in the cartilaginous cores of the long bone during embryonic and fetal development and in the appendicular skeleton (6-13 weeks). The Fritz protein is a member of the Secreted frizzled-related protein (sFRP) protein family.