In the Golgi, CER can be phosphorylated by CER kinase (Rovina et al. 2009), glycosylated by glucosyl or galactosyl CerS (Raas-Rothschild et al. 2004), or acquire a variety of neutral or charged head groups under the catalysis of what could be called generically SLSs, to form various complex phosphosphingolipids. Phylogenetic analyses have identified at least 4 clades of SLS (Huitema et al. 2004; Denny et al. 2006).