Alantolactone is a sesquiterpene lactone disrupts the Cripto-1/ActRII complexes, resulting in an induction of activin/SMAD3 signaling. Alantolactone inhibits proliferation in cancer cells with no affect on normal cells;Alantolactone is a sesquiterpene lactone disrupts the Cripto-1/ActRII complexes, resulting in an induction of activin/SMAD3 signaling. Alantolactone inhibits proliferation in cancer cells with no affect on normal cells