Using Kaplan–Meier plotter, an online database containing the gene expression information of around 2000 lung cancer patients, Wang et al. [61] found that high SPHK1 mRNA expression was significantly correlated with worse overall survival, while high SPHK2 mRNA expression was in favor of better overall survival, in keeping with some of the findings of other studies mentioned above. This evidence concerns the gene SPHK2 and lung cancer.