ST8SIA1 and Alzheimer disease: Gangliosides are directly involved in AD pathology, e.g. the concentration and composition of gangliosides are altered in the brains of AD patients and in transgenic mouse models of AD [19], [20], [21]; ganglioside clusters in neuronal membranes take part in the formation of amyloid fibrils [13], [15], [16]; GM1 drastically increases Aβ production [22], binds to Aβ and is discussed to act as a seed for Aβ aggregation in amyloid plaques [23], [24], [25]; and Aβ aggregation as well as Aβ induced cell death are reduced in AD-model mice lacking GD3S [14].