Alpha-N-acetylgalactosamine-specific lectin. The oligomeric form has Ca(2+)-dependent hemagglutination activity towards sheep erythrocytes. Its hemagglutination activity is inhibited by various monosaccharides, oligosaccharides and glycopeptides, including inhibition by GalNAc, blood group A trisaccharide, Tn antigen, mucin and asialomucin. Monomer, homodimer and homooligomer.