Although the exact mechanism behind the CSC-inhibitory activity of CEP-1347 and the role of MLKs therein remain to be elucidated, our findings, together with the solid safety records of the drug in humans, suggest that adding CEP-1347 to current cancer treatment regimens is a rational and feasible approach to preventing post-treatment recurrence and/or metastasis from CSCs surviving treatment, in particular from those dependent on JNK for their stem cell state. The gene discussed is MAPK8; the disease is cancer.