The SphK2 isozyme is gaining much prominence as a cancer therapeutic target and may prove to have greater efficacy as an oncotarget than its comparative isozyme hSphK1, which is driving the development of the hSphK2 inhibitors (Table 2), and the ongoing clinical trials of the hSphK2 ABC294640 (Table 4). Here, SPHK2 is linked to cancer.