Various glycolipid glycans have been reported to be characteristically expressed in cancer cells and serve as cancer markers. Among them, gangliosides, which are sialic acid-containing glycosphingolipids, are characteristically expressed in cancers derived from neural crest and are used not only as cancer markers but also as therapeutic targets. Gangliosides are highly expressed in the nervous system of vertebrates and universally expressed on the membranes of most cells in the body. However, mature gangliosides with extended core structures are abundant in the nervous system, while relatively short-chain disialyl gangliosides are specifically expressed in cancer cells, which has been proven to be effective as targets for antibody therapy. On the other hand, globo-series glycolipids with different core structures have also been shown to play roles in cell differentiation, immune system, and as cancer-related antigens, and are attracting attention [1]. On the other hand, many reports have been made on the regulatory effects of glycolipids on signal regulation and cell phenotypes through their association with membrane functional molecules such as integrins in lipid rafts [2] (Fig. 101.1). In other words, they are assumed to play important roles in various tissue differentiation and cell fate determination and are forming a fundamental and important area for elucidating glycan functions.