SPHK1 and cancer: Sphingolipid metabolism, especially sphingolipid rheostat (ceramide/sphingosine/S1P ratio), regulating enzymes (mostly SK1/SK2) and/or S1P1-5 receptors; have been proposed as diagnostic, prognostic, and/or severity biomarkers in several cancers (breast, colon, pancreas, liver, glioma, etc.).