Ganglioside GM2 is a glycosphingolipid component of cellular membranes, primarily the plasma membrane.{43702} Gangliosides isolated from apoptogenic glioblastoma multiforme (GBM) cells are enriched in ganglioside GM2 compared with nonapoptogenic GBM cells, and ganglioside GM2 induces activated T cell death when used at a concentration of 150 ?g/ml in vitro.{61125} Serum ganglioside GM2 levels are increased in patients with breast cancer or cholangiocarcinoma.{61126,61127} Levels of ganglioside GM2 are elevated in the brain of patients with Sandhoff disease, as well as feline and mouse models of the disease.{40891} Ganglioside GM2 accumulates in the lysosomes of individuals with Tay-Sachs disease and GM2-activator deficiency, as well as in the CNS of patients with and animal models of mucopolysaccharide storage disorders and Niemann-Pick disease types A, C1, and C2.{40891,43703} This product contains ganglioside GM2 molecular species with primarily C18:0 fatty acyl chain lengths. As this product is derived from a natural source, there may be variations in the sphingoid backbone.