The brilliant research of Dr. Earl Sutherland and his colleagues has had a broad impact on many areas of biology. Among the fields in­ fluenced rather late by the insights arising from this work were im­ munology and oncology. Although research relating cyclic AMP metabol­ ism to the development and manifestations of the immune response and the control of mammalian cell growth is relatively recent, the growth of knowledge in these areas has been rapid and there is already a considera­ ble amount of empirical information. This conference provided an oppor­ tunity to collate and begin to interpret that information. A deliberate at­ tempt was made to bring together investigators nominally involved in im­ munology, biochemistry, pharmacology, or cellular biology for in many instances parallel observations are being obtained in these fields. For ex­ ample, the immunologist studying the transformation of lymphocytes by antigens or mitogens is carrying out experiments that are very close to those of the biologist studying the growth of cells in culture; in both cases, the phenomena they observe are modulated by changes in the in­ tracellular level of cyclic nucleotides. Many other examples of closely analogous experiments in different fields could be cited, but perhaps the point is clear.