The underlying reason some ionophores work against cancer stem cells and other ionophores do not is poorly understood but it is possible that other ionophore-independent activity target key processes associated with stemness, for instance, (i) SAL induces ER Ca2+ depletion up-regulating C/EBP homologous protein (CHOP), which inhibits Wnt signaling by down-regulating β-catenin [168]. Here, DDIT3 is linked to cancer.