Sphingolipids represent a major class of lipids that are important components of membranes in eukaryote cells. Since their discovery in 1876, sphingolipids were considered for a long period as inert structural components in membrane. However, intensive research on metabolism and function has found that several sphingolipids including ceramide, sphingosine, ceramide-1-phosphate and sphingosine-1-phosphate play important roles in regulating a wide range of signaling pathways (Kim et al., 2009; Morales et al., 2007; Ogretmen and Hannun, 2004; Zheng et al., 2006).
