It has to be tiny enough to get through the bloodstream, it's got to be small enough to penetrate the tumor tissue, and it's got to be tiny enough to be taken up inside the cancer cell.
Deve essere abbastanza piccola per passare nei vasi sanguigni, abbastanza piccola per penetrare il tessuto cancerogeno e abbastanza piccola per occupare  l'interno della cellula tumorale.