Influenza virus membranes contain two glycoproteins&colon; hemagglutinin and neuraminidase. Such components include fibronectin, collagen, glycosaminoglycans, elastin, glycoproteins and proteoglycans. Not all natural oligosaccharides occur as components of glycoproteins or glycolipids. These antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending on the blood group system. Glycans can be found attached to proteins as in glycoproteins and proteoglycans. Endothelial selectins bind carbohydrates on leukocyte transmembrane glycoproteins, including sialyl-Lewis. Metastatic cancer cells often express a high density of sialic acid-rich glycoproteins. Some modifications can produce hydrophobic lipoproteins, or hydrophilic glycoproteins. Cardiomyocytes are linked to the basement membrane via specialised glycoproteins called integrins. Proteins are also used in membranes, such as glycoproteins. It is unmineralized and consists of collagen, glycoproteins, and proteoglycans. It consists of a monomolecular layer composed of identical proteins or glycoproteins. Then, the cells begin to display surface HIV glycoproteins, which are antigenic. MUC16 is a member of the mucin family glycoproteins. The nucleocapsid, in turn, is enveloped within a host-derived membrane modified with two viral glycoproteins.