PSG3 is a symbol for the gene, Pregnancy specific beta-1-glycoprotein 3, in humans. Other names include: Pregnancy-specific beta-1-glycoprotein 3; PSBG-3; Pregnancy-specific glycoprotein 3; Carcinoembryonic antigen SG5; PS-beta-G-3. The encoded protein has an amino acid length of 428 and a mass of 47.9 kDa. Other isoforms may exist. PSG3 is a member of the Immunoglobulin superfamily, CEA family. This gene shares homology with other species, including: Frog.