（Structural unit shared by (neurological) sphingolipids. Fatty acids have the structure of an acid amide bond on the amino group of sphingosine. If sugar is bound to them, they become sphingolipids, and if choline phosphate is bound to them, they become (neuro)sphingolipids. Ceramides are intermediate metabolites of sphingolipids and are particularly important in biosynthesis. It is present in only small amounts outside of platelets. It is a colorless transparent liquid, highly efficient moisturizer with the ability to initiate cells, promote cell metabolism, and prompt regular regeneration of keratin. It is widely used in cosmetics for its moisturizing and anti-aging effects. In tumor metabolism, CERAMIDE also has the ability to initiate cells and promote the proliferation and metastasis of tumor cells. Therefore, it is recommended that tumor patients or people with high risk factors for tumors avoid using cosmetics containing CERAMIDE, especially moisturizing cosmetics. Currently, many cosmetic products are sold as such.