CERK and Alzheimer disease: Moreover the S1P concomitant genes including ceramide synthases (CERS-1, CERS-2) and Sphingosine-1-phosphate lyase (SGPL-1) were found to be up-regulated in AD patients, whereas sphingosine kinases (SphK-1, SphK-2), ceramide kinase (CERK), and anti-apoptotic Bcl-2 were found to be reduced [100].