Goals for the next year will be to determine the effect of 5-thio- D-glucose on D-glucose transport of cancer cells and perhaps in selected microorganisms. Investigation will be made of 5-thio-D-glucose and its 1- and 6-phosphate as substrates for enzymes. UDP-5-thio-D-glucose will be made and examined as a transferase substrate. Radioactive 5-thio-D- glucose will be made and its rate of excretion from rats will be measured after oral and intravenous administration.