ABO encodes the human gene, ABO blood group (transferase A, alpha 1-3-N-acetylgalactosaminyltransferase; transferase B, alpha 1-3-galactosyltransferase). It may also be known as: Histo-blood group ABO system transferase; Fucosylglycoprotein 3-alpha-galactosyltransferase; Fucosylglycoprotein alpha-N-acetylgalactosaminyltransferase; Glycoprotein-fucosylgalactoside alpha-N-acetylgalactosaminyltransferase; Glycoprotein-fucosylgalactoside alpha-galactosyltransferase; Histo-blood group A transferase; A transferase; Histo-blood group B transferase; B transferase; NAGAT; A3GALT1. The encoded protein is an enzyme with an amino acid length of 354 and a mass of 40.9 kDa. Other isoforms may exist. ABO is a member of the Glycosyltransferase 6 family. Homologs of this gene exist in other organisms, including: Frog.