Sphingosine kinases 1 and 2 (SPHK1/2) phosphorylate sphingosine to S1P, with SPHK1 being localized in the cytoplasm and SPHK2 in the nucleus, endoplasmic reticulum (ER), mitochondria, and, in cancer cells, in the plasma membrane (Diaz Escarcega et al., 2021). The gene discussed is SPHK1; the disease is cancer.