Digitalis; impinges on more than just the (ion-) pump.

Some forms of digitalis, such as digitoxin, inhibits proliferation and induces apoptosis in cancer cells in clinically relevant concentrations. Recently, it has been demonstrated that digitalis, in addition to inhibiting the Na(+)/K(+)-ATPase, also signals through the pathways of the epidermal growth factor receptor (EGFR). Digitalis has complex dose-dependent mechanisms of action involving many signaling systems and the relevance of this for the anticancer effects are discussed.