b-glucuronidase-catalyzed activation of anticancer prodrugs. Cancer chemotherapy is associated with severe side effects, which may be reduced by selective liberation, at the tumour site, of cytotoxic agent from a non-toxic prodrug. This paper presents the actual level of knowledge on anticancer therapy strategies using b-glucuronidase as a side specific activator (Prodrug Monotherapy, PMT; Antibody Directed Enzyme Prodrug Therapy, ADEPT; Gene Directed Enzyme Prodrug Therapy, GDPT).