As a key enzyme of sphingolipid metabolism, a highly selective small molecule inhibitor of SphK, 3-(4-chlorophenyl)-adamantane-1-carboxylic acid (pyridin-4-ylmethyl)amide (named as ABC294640), has been recently developed 18,19, and shows significant anti-tumor effects on a variety of cancers 20-24. Here, SPHK1 is linked to neoplasm.