Arenobufagin is a bufanolide steroid found in the Argentine toad Bufo arenarum. This compound exhibits anticancer chemotherapeutic and anti-angiogenic properties, but is also cardiotoxic, inhibiting cardiovascular Na+/K+ pumps. In cellular models, arenobufagin induces autophagy and apoptosis, inhibiting tumor growth through indirect inhibition of the PI3K/Akt/mTOR signaling pathway. Arenobufagin also inhibits VEGFR2 directly through blockade of ATP-binding sites.