ABC294640 (Opaganib) is an orally bioavailable, selective inhibitor of sphingosine kinase 2 (SPHK2 or SK2). Sphingosine kinases phosphorylate sphingosine producing the bioactive lipid sphingosine 1-phosphate which has roles in cell proliferation and cell motility. Sphingosine kinases are up-regulated in numerous forms of cancer and ABC294640, alone or in combination, has been shown to suppress growth in kidney, breast, liver, colon, and lung cancer cell lines.