The Forssman antigens are glycolipids that very closely resembles the Globo H antigen as they share an identical Gb4 tetrasaccharide core. It is species specific as expressed in some mammals (e.g., sheep, dogs, horses, etc.) but not in others (rabbits, pigs, humans, etc.). Interestingly, it is present in several forms of human cancers making it a potential candidate for cancer therapy.