OBJECTIVES: To assess whether qualitative alteration of cyclic AMP (cAMP)-binding proteins of tumors is correlated with "unresponsiveness" to dibutyryl cyclic AMP (DBcAMP)-induced tumor regression in vivo; to assess the apparent correlation between nuclear translocation of cAMP-binding proteins and DBcAMP-induced tumor regression in vivo. BIBLIOGRAPHIC REFERENCE: Cho-Chung, Y.S. and Clair, T.: Altered Cyclic AMP-binding and db Cyclic AMP-unresponsiveness in Vivo. Nature 265: 452-454, 1977.