SPHK2 and colonic neoplasm: The importance of sphingosine kinase-mediated signaling in oxaliplatin resistance in colon cancer was also confirmed by Nemoto et al. [86] who demonstrated that colon cancer RKO cells with high activity and expression of SphK1 but also SphK2 exerted poor sensitivity to treatment with oxaliplatin in comparison with HCT116 colon cancer cells with low activities of both SphK isoforms that were sensitive to oxaliplatin.