Lectins are a diverse type of glycoproteins or carbohydrate-binding proteins that have a wide distribution to various species.Because of the ability to agglutinate red blood cells,they are named leetins.A lectin can specially identify and exclusively bind to a certain kind of saccharide groups,which is its most maj or characteristic.To the occurrence and development of carcinoma,a sort of lectin has an indispensable effect,namely cancerlectin.