In addition to examining in more detail the influence of antineoplastic agents upon the metabolism, distribution, and binding of drugs and their toxicity, the metabolic fate of selected antineoplastic agents will be studied. Carcinolytic agents will be employed as model substrates for the in vitro measurements of microsomal enzyme activity. The biliary excretion model will be extended to study excretion of antineoplastic agents and their metabolites with subsequent identification by mass spectral techniques.