A group of compounds found in marihuana have been shown to significantly prolong the survival time of tumor bearing mice and to inhibit the uptake of H3 thymidine in these tumors both in vivo and in vitro. Lewis lung tumor cells either grown in tissue culture or as isolated cells will be used to evaluate the activity of delta9-THC and its congeners. Furthermore, the elucidation of possible site(s) of drug action will be attempted utilizing radiolabel incorporation into RNA, DNA, and protein A further division of these parameters will be undertaken once the level at which the drug is working is determined (e.g., nucleotide uptake and phosphorylation). Preliminary observations indicate that tolerance to these compounds does develop; therefore an evaluation of drug tolerance in Lewis lung tumor and mouse bone marrow cells will be carried out.