Investigating the immune properties of basidiolipids, i.e., glycoinositolphosphoceramides (GIPC) of basidiomytes, higher mushrooms, it was detected that sera of normal adult human subjects contained IgG2 and IgM heterophile antibodies (hetAbs) that immunoreacted with these lipids. However, this immune recognition was not shared by the glycolipids of all mushroom species. The basidiolipids of Amanita virosa (eng., death cup) and Cantharellus cibarius (engl., chantarelle), of all mushroom species studied, did not bind antibodies of normal human sera. In addition, only certain basidiolipids of the other mushroom species that have been investigated, i.e., Agaricus bisporus (engl., field mushroom), Calvatia exipuliformis engl., puffball), Lentinus edodes (jap., Shiitake), Leccinum scabrum (engl., red birch boletus), and Pleurotus ostreatus (engl., oyster mushroom), immunoreacted with the human hetAbs. The basidiolipids that were recognized by the human hetAbs had either terminal Galalpha1-6Gal < or Galbeta1-6Man< epitopes. Enzymatic destruction of the respective carbohydrate epitopes abolished the previous immune reactivity. It is assumed that contact with non human antigens causes generation of the anti-basidiolipid antibodies.