Gangliosides are acidic glycosphingolipids that form lipid rafts in the outer leaflet of the cell plasma membrane, especially in neuronal cells in the central nervous system. They participate in cellular proliferation, differentiation, adhesion, signal transduction, cell-to-cell interactions, tumorigenesis and metastasis. The accumulation of gangliosides has been linked to several diseases. Ganglioside GD1a is the major ganglioside of the nervous system. It is converted to GM1 by bacterial, viral and mammalian sialidases. It is a differentiation marker for cell growth.