SPHK1 and acute myeloid leukemia: In recent works [5,15], we evaluated the possible association of SL metabolism with drug resistance in AML, wherein we showed that chemotherapy selection pressure (DNR, vincristine, VCR) enhanced expression of AC, glucosylceramide synthase (GCS), and sphingosine kinase 1 (SPHK1), enzymes that catalyze ceramide hydrolysis, glycosylation, and formation of sphingosine 1-phosphate (S1P), respectively.