The amount of a polypeptide N-acetylgalactosaminyltransferase 11 when measured in blood serum. The trait is OBA_2041661 (level of polypeptide N-acetylgalactosaminyltransferase 11 in blood serum). Also known as: blood serum polypeptide N-acetylgalactosaminyltransferase 11 amount.