Sphingosine kinase (SPHK) is an important enzyme in the sphingolipid metabolic pathway. SPHKs phosphorylate D-erythro-sphingosine to yield sphingosine-1-phosphate (S1P). To date two isoforms of SPHK, SPHK1 and SPHK2, have been identified & characterized from mammalian cells.{14483} Among them, SPHK1 has been implicated to play a role in signaling pathways in mast cells and in TNF-?-triggered responses of fibroblasts and epithelial cells. Recent findings also indicate that SPHK1 mRNA levels are increased in a variety of human tumors. Brain tumors with high SPHK1 expression correlated with poor survival of patients and high expression of SPHK1 appears to be an oncogenic event required for erythroleukaemic progression.{14534,14535} Thus SPHK is a potential therapeutic target for the control of cancer and inflammation.{14534,14535}